OT: Ping Trevor - Turntable recommendations

[Noddy]

Hey Trev. Could use your help if you feel like offering it.

My kid's birthday is coming up in a couple of months and he'd like a new
stereo. He got a big kick out of his old Garrand 3500 based stereo that
I talked about here some time ago, but it's started to be a bit
unreliable and he'd love something a bit better. He basically just wants
a turntable as he loves vinyl and has no interest in CD's or tapes, and
with that in mind I have 2 questions for you.

Firstly, is there anything new on the market today that you would
recommend? I'm not looking for high end stuff, but don't want cheap
rubbish either. I'm not fussed about brands and I dare say neither is
he. It doesn't have to be anything elaborate. Just want something that
sounds reasonable. If you had any recommendations of a system that could
be put together on a budget of a thousand bucks I'd be all ears.

Secondly, if you don't think new stuff in that price range today is
worth owning, could you recommend any second hand stuff to look out for?
I see the odd 70's or 80's vintage Marantz, Pioneer or Yamaha hifi
systems come up on Marketplace occasionally, and wondered if something
of that nature (or anything else you could recommend) would be a better
bet instead?

Appreciate any and all advice you may be able to offer.



--
--
--
Regards,
Noddy.

[alvey]

For the kid hey Fraudster? Sure it is. I believe you. Honest.



alvey
And what teenage boy *wouldn't* want an old, 2nd hand music player that
takes up half a room and produces seriously shithouse sound for his
birthday?

[Ozix]

alvey wrote:
>
>
>
> alvey
> And what teenage boy *wouldn't* want an old, 2nd hand music player that
> takes up half a room and produces seriously shithouse sound for his
> birthday?
>

My niece is into vinyl. She loves 70s music: T.Rex, Ramones, Daddy Cool
et cetera.

[Mighty Mouse]

alvey wrote:
> Noddy wrote:
>> Hey Trev. Could use your help if you feel like offering it.
>>
>> My kid's birthday is coming up in a couple of months and he'd like a
>> new stereo. He got a big kick out of his old Garrand 3500 based
>> stereo that I talked about here some time ago, but it's started to be
>> a bit unreliable and he'd love something a bit better. He basically
>> just wants a turntable as he loves vinyl and has no interest in CD's
>> or tapes, and with that in mind I have 2 questions for you.
>>
>> Firstly, is there anything new on the market today that you would
>> recommend? I'm not looking for high end stuff, but don't want cheap
>> rubbish either. I'm not fussed about brands and I dare say neither is
>> he. It doesn't have to be anything elaborate. Just want something
>> that sounds reasonable. If you had any recommendations of a system
>> that could be put together on a budget of a thousand bucks I'd be all
>> ears.
>>
>> Secondly, if you don't think new stuff in that price range today is
>> worth owning, could you recommend any second hand stuff to look out
>> for? I see the odd 70's or 80's vintage Marantz, Pioneer or Yamaha
>> hifi systems come up on Marketplace occasionally, and wondered if
>> something of that nature (or anything else you could recommend) would
>> be a better bet instead?
>>
>> Appreciate any and all advice you may be able to offer.
>
> For the kid hey Fraudster? Sure it is. I believe you. Honest.

not a good idea buying 40 or 50 year old electronic equipment, lol. but
his budget is too low for a decent HiFi sound system new.

>
>
>
> alvey
> And what teenage boy *wouldn't* want an old, 2nd hand music player
> that takes up half a room and produces seriously shithouse sound for
> his birthday?
>

I have Kef Concerto main speakers for the TV surround sound system,
paired with a B&W centre and JBL rears. sounds good!

--
Have a nice day!..

[Daryl]

Its popularity has increased, I've seen turntables advertised on TV
recently.



--
Daryl

[Keithr0]

On 17/02/2024 1:16 pm, Ozix wrote:
> alvey wrote:
>>
>>
>>
>> alvey
>> And what teenage boy *wouldn't* want an old, 2nd hand music player
>> that takes up half a room and produces seriously shithouse sound for
>> his birthday?

Get with the program granddad, all the cool kids are into vinyl these days.

> My niece is into vinyl. She loves 70s music: T.Rex, Ramones, Daddy Cool
> et cetera.

One of my grandsons has a large collection of Queen stuff - on vinyl. He
is willing to spend real money on rare items, his brother is into vinyl
too but prefers Slipknot.

[Noddy]

On 18/02/2024 10:01 am, Keithr0 wrote:

> One of my grandsons has a large collection of Queen stuff - on vinyl. He
> is willing to spend real money on rare items, his brother is into vinyl
> too but prefers Slipknot.

My kid is into 60's & 70's pop/rock. Beatles, Stones, Credence, Pink
Floyd, and the Doors. Particularly The Doors. He loves vinyl as there's
something about it he finds intriguing, and he decorates his bedroom
walls with the album covers.

[Keithr0]

The electrolytic capacitors would be suspect, but the rest should be OK
if it has been kept in a reasonable environment, and not abused.

>> alvey
>> And what teenage boy *wouldn't* want an old, 2nd hand music player
>> that takes up half a room and produces seriously shithouse sound for
>> his birthday?
>>
>
> I have Kef Concerto main speakers for the TV surround sound system,
> paired with a B&W centre and JBL rears. sounds good!
>

I've a pair of halfway decent speakers that I bought in 1988, even
though we've moved house 7 times since then, they still sound just fine.

[Keithr0]

I met the bass player from the Doors once in a pub on the south coast of
Ireland. He was living in a small village there at the time (about 20
years ago).

[Noddy]

Yeah, I don't think you did.

The Doors were one of the few groups who never actually had a bass
player. The majority of their bass lines were played on an electric
keyboard bass by their keyboard player Ray Manzarek who as far as I'm
aware never lived in Ireland. Whatever bass parts he didn't play were
performed by a session musician in the studio.

[Xeno]

A bullshit artist exposing another’s bullshit tale, incredible!

____
Xeno

[Trevor Wilson]

**There is nothing available, new, for less than around $500.00 that is
worth bothering with. JB Hi Fi specialise is selling utter rubbish.

Which leaves with, IMO, the best value for money, quality second hand
stuff. Obviously, that presents it's own risks, but turntables are
generally operated under a very low stress environment and most can be
expected to last many decades.

Personally, the two brands I like most are Denon (Japan) and Dual
(Germany). Dual is difficult, as the company no longer exists and there
are aspect of some models that can make repair impossible. For instance:

The original Dual 505 was a fine turntable, but fitted with a
diabolically bad headshell. However, the Dual 505-2, 3, 4 addressed that
problem quite effectively. The 505 was a belt drive unit and drive belts
are easily available, but the speed control belt is not. Dual also made
a number of direct drive units and they are generally pretty decent. I
would caution again the much older, rim drive Duals, as the idler can be
very difficult to find. Motors are easy to rebuild. That said, the
mechanisms are complicated (they're full auto) and are of such an age
that a full strip down and re-lube will be required. OTOH, the 505 (and
others in that range) are semi-auto and far simpler to sort out.

Denon make all direct drive units. I like them. A lot. I presently have
11 of the suckers. I buy them in from Japan, tart them up a bit and
re-sell. The downside is that they need a 230VAC - 110VAC step-down
transformer (about $35.00) to work in Oz. The motors in Denons are works
of art. Smooth as butter and they last forever. They come in manual,
semi-auto and full auto. Because they're mechanisms are simpler than
most, even their full auto models are a good buy.

Technics are another, very popular, option. IMO, they are generally a
bit over-priced, compared to Denon, due to their popularity with the
disco people. Still, they are quite decent for the most part. Beware:
Technics have built some real shit in their low end models.

Rega is a fascinating Pommy success story. Fully manual, but excellent
performers, built fairly cheaply. Tone arms are a one piece, magnesium
casting. Genius. Counterweight is solid tantalum. Available new and used
(the Rega Plannar 3 has been around for 40 years).

Anyway, feel free to give me a call to discuss your needs (bus hours
please). 02 9589 1001

I am always happy to talk the hind leg off a mule about audio.


--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

[Trevor Wilson]

On 19/02/2024 8:07 am, Trevor Wilson wrote:
Because they're mechanisms are simpler than
> most, even their full auto models are a good buy.

**Oh fuck. Is English my second language. That should read:

"....their mechanisms are....."

Smacks head.

[Keithr0]

On 19/02/2024 7:07 am, Trevor Wilson wrote:

> The downside is that they need a 230VAC - 110VAC step-down transformer
> (about $35.00) to work in Oz.

If they are Japanese domestic items, they will be 100vac rather than 110
but running 10% high doesn't usually cause problems these day.

If anybody needs a big 110v stepdown transformer, I've got one gathering
dust in the garage.

[Trevor Wilson]

**You are, of course, correct. It was a typo on my part. The
transformers I purchase are 100VAC types. And they aren't big. They
don't need to be.

[alvey]

Trevor Wilson wrote:
> On 16/02/2024 3:41 pm, Noddy wrote:

> I am always happy to talk the hind leg off a mule about audio.

You're already doing that.


alvey

[Noddy]

Thank you very much indeed Trevor. This kind of detailed response is
exactly why I asked you :)

I've taken all this on board and will keep my eye out & see what I can
find, and I'll give you a call if I come across anything specific that
needs further investigation.

Thanks again. It's greatly appreciated.

--
--
Regards,
Noddy.

[Trevor Wilson]

**In case you didn't pick up on what I said, I have several Denons that
will be for sale, along with a couple of Direct drive Duals and a couple
of Technics. Except for the Denons, they're all 230VAC models. The
Denons are 100VAC versions, but I can supply suitable step-down
transformers at cost price.

I can post photos if you wish.

[lindsay]

On 19/02/2024 11:10 am, Noddy wrote:

>>

FWIW, I have mums Technics SL-D3 XA which I've been meaning to sell. Mum
bought it home from a holiday to Japan. Has an Aussie voltage switch
under the platten. Was working fine last time she used it, and I
recently plugged it in, lifted the tone arm, and around she went. :-)
Seems in good nick, minimal scuffing to the cover. No idea what the
cartridge and belt are like, so no guarantees. Trevor suggested it may
be worth up to $300, happy to let it go for $200 for you. I need the
shelf space :-)

https://imgur.com/a/OuzlhP1

Mig bottle not included. :-D


>
> --
> --
> Regards,
> Noddy.
>

[Noddy]

No worries. I did notice, and I see Lindsay's just chimed in with a
Technic for sale. Given that he's closer I'll grab that from him, but
I'll deal with you if there's anything I need for it.

Thanks again for the help.


--
--
Regards,
Noddy.

[Noddy]

Sounds like a deal to me. I'll take it thanks. I'm not in a hurry, so
I'll message you in a day or so and make a time to collect it.

> Mig bottle not included. :-D

Bastard.

[lindsay]

Cool.!! Please note, i'm off to NZ on Sunday for 2 weeks, so it's this
week, or 3 weeks from now... :-)

>
>> Mig bottle not included. :-D
>
> Bastard.

Been called a lot worse, like late for dinner :-)
>

[Noddy]

I've got stuff on this week, so enjoy your trip and I'll see you when
you get back.

[Trevor Wilson]

**No probs. Lindsay's turntable is a very simple, belt drive model. Not
much to go wrong and parts should be generally available if something does.

[Noddy]

Cool. Now I just need an amp and some speakers :)

[Mighty Mouse]

not necessarily. with the repetitive cycle of heating and cooling from
use dry joints develop, semiconductors fail, corrosion on contacts,
etc., and amps that old have mechanical controls. the tracks wear on the
pots and the shaft lube dries out. lots of things.

>
>>> alvey
>>> And what teenage boy *wouldn't* want an old, 2nd hand music player
>>> that takes up half a room and produces seriously shithouse sound for
>>> his birthday?
>>>
>>
>> I have Kef Concerto main speakers for the TV surround sound system,
>> paired with a B&W centre and JBL rears. sounds good!
>>
> I've a pair of halfway decent speakers that I bought in 1988, even
> though we've moved house 7 times since then, they still sound just fine.

no reason why they wouldn't, except speaker suspensions (especially bass
drivers) can lose rigidity over time which can cause diaphragm flapping
and poling. also the failure of crossover components.

[Trevor Wilson]

**Now you need to call me and discuss. Unfortunately, I sold a pair of
speakers last week that would have been perfect.

[Mighty Mouse]

err... no. SL-D3 is a direct drive

[Trevor Wilson]

**Quite so. It's written right there on the front and the back.

[Smacks head]

[lindsay]

Yep, goes to show how much i've been paying notice.. i said it may need
a new belt... :-) It's been sitting on the shelf with a dust rag over
it for at least a year, which is when I plugged it in, and took the
photos in preparation to advertise it.

[lindsay]

no worries... one thing I just remembered, it has an old power plug on
the end.. looks like Bakerlite. Would have been fitted when it was
bought back from Japan. You may want to swap it.. just letting you know.
>

[Maximus]

if it's Direct Drive it's NOT belt drive! surprised you don't know that

>
> [Smacks head]
>


--
“Atheism is the birth right of all human, remember that!”- hhyapster 7.4.23

"Christianity cannot prevail against reason, fact, and knowledge"

"Religion is not about truth, it's about lifestyle"

"God is a convenient explanation for what man does not understand.
The less that's inexplicable, the less the need for God."

[Mighty Mouse]

It doesn't have a belt. it's a Direct Drive turntable

[Mighty Mouse]

p.s. pull the platter off and you will see

[lindsay]

I know. Thats what I, and Trevor, said above. No need to correct us
after we've corrected ourselves.
>

[Noddy]

On 20/02/2024 4:39 am, Trevor Wilson wrote:
> On 19/02/2024 8:22 pm, Noddy wrote:

>> Cool. Now I just need an amp and some speakers :)
>>
>>
>>
>
> **Now you need to call me and discuss. Unfortunately, I sold a pair of
> speakers last week that would have been perfect.

I'll give you a yell once I pick the turntable up from Lindsay.

[Noddy]

No wukkas. I'll sort it out.

[Mighty Mouse]

that was not obvious

[Keithr0]

On 20/02/2024 10:19 am, Maximus wrote:

Uh oh yet another felix 'nym

[Mighty Mouse]

Keithr0 wrote:
> On 20/02/2024 10:19 am, Maximus wrote:
>
> Uh oh yet another felix 'nym
>

wasn't meant to happen

[Keithr0]

On 19/02/2024 9:57 pm, Mighty Mouse wrote:

>>> not a good idea buying 40 or 50 year old electronic equipment, lol.
>>> but his budget is too low for a decent HiFi sound system new.
>>
>> The electrolytic capacitors would be suspect, but the rest should be
>> OK if it has been kept in a reasonable environment, and not abused.
>
> not necessarily. with the repetitive cycle of heating and cooling from
> use dry joints develop, semiconductors fail, corrosion on contacts,
> etc., and amps that old have mechanical controls. the tracks wear on the
> pots and the shaft lube dries out. lots of things.

Pots are easy to check, just wind them from end to end and listen for
crackles, replacement is a minor job. Corrosion on contacts will not
occur if it has been kept in a reasonable environment. Dry joints do not
develop, they exist from poor soldering, broken joints can occur from
heat cycling in badly designed or constructed equipment, but a good
thump will usually detect it.

The thing is to check it before buying or get someone who knows what
they are doing to check it for you.

[Mighty Mouse]

Keithr0 wrote:
> On 19/02/2024 9:57 pm, Mighty Mouse wrote:
>
>>>> not a good idea buying 40 or 50 year old electronic equipment, lol.
>>>> but his budget is too low for a decent HiFi sound system new.
>>>
>>> The electrolytic capacitors would be suspect, but the rest should be
>>> OK if it has been kept in a reasonable environment, and not abused.
>>
>> not necessarily. with the repetitive cycle of heating and cooling
>> from use dry joints develop, semiconductors fail, corrosion on
>> contacts, etc., and amps that old have mechanical controls. the
>> tracks wear on the pots and the shaft lube dries out. lots of things.
>
> Pots are easy to check, just wind them from end to end and listen for
> crackles, replacement is a minor job.

but who is going to buy an amp that needs to have the pots replaced,
unless they're an electronics technical person who can do it themselves,
which noddy is not, as he has amply shown in this ng. also, the person
selling the amp may have just squirted the pots to keep them going ok
for a while.

> Corrosion on contacts will not occur if it has been kept in a
> reasonable environment.

which many are not, or maybe used in high humidity locations.

> Dry joints do not develop, they exist from poor soldering, broken
> joints can occur from heat cycling in badly designed or constructed
> equipment, but a good thump will usually detect it.

IOW dry joints develop over time, as I said. you could buy an amp that
works fine when you purchase it, then dry joints appear some time later
in normal use

>
> The thing is to check it before buying or get someone who knows what
> they are doing to check it for you.

that will not necessarily guarantee you won't have trouble with it
later. amps made in the 70's or 80's are now 50 odd years old! who in
their right mind would buy a 50 year old amp and expect to have no
problems with it, especially when amps only a few years old fail for all
sorts of reasons. semiconductors can fail, as I said in my original
post, and are far more likely to do so having had 50 years of use.

[Keithr0]

On 22/02/2024 11:52 am, Mighty Mouse wrote:
> Keithr0 wrote:
>> On 19/02/2024 9:57 pm, Mighty Mouse wrote:
>>
>>>>> not a good idea buying 40 or 50 year old electronic equipment, lol.
>>>>> but his budget is too low for a decent HiFi sound system new.
>>>>
>>>> The electrolytic capacitors would be suspect, but the rest should be
>>>> OK if it has been kept in a reasonable environment, and not abused.
>>>
>>> not necessarily. with the repetitive cycle of heating and cooling
>>> from use dry joints develop, semiconductors fail, corrosion on
>>> contacts, etc., and amps that old have mechanical controls. the
>>> tracks wear on the pots and the shaft lube dries out. lots of things.
>>
>> Pots are easy to check, just wind them from end to end and listen for
>> crackles, replacement is a minor job.
>
> but who is going to buy an amp that needs to have the pots replaced,
> unless they're an electronics technical person who can do it themselves,
> which noddy is not, as he has amply shown in this ng. also, the person
> selling the amp may have just squirted the pots to keep them going ok
> for a while.

Any tech that charges more than half an hour to replace a pot is ripping
you off. More than one pot, add 10 minutes would be more than adequate.
Cost of a new pot ~$2. Worthwhile if it is good gear at a reasonable price.

>> Corrosion on contacts will not occur if it has been kept in a
>> reasonable environment.
>
> which many are not, or maybe used in high humidity locations.

If it's not a bottom feeding el cheapo device the plating should handle
most indoor environments.

>> Dry joints do not develop, they exist from poor soldering, broken
>> joints can occur from heat cycling in badly designed or constructed
>> equipment, but a good thump will usually detect it.
>
> IOW dry joints develop over time, as I said. you could buy an amp that
> works fine when you purchase it, then dry joints appear some time later
> in normal use

A dry joint is a solder joint not properly done in the first place.

https://www.nextpcb.com/blog/dry-solder-joint

They are rare on PCBs which, these days, are usually soldered
automatically. They are usually caused by too low a soldering iron
temperature, not enough flux, or most likely by trying to solder to a
contaminated surface or component.

>> The thing is to check it before buying or get someone who knows what
>> they are doing to check it for you.
>
> that will not necessarily guarantee you won't have trouble with it
> later. amps made in the 70's or 80's are now 50 odd years old! who in
> their right mind would buy a 50 year old amp and expect to have no
> problems with it, especially when amps only a few years old fail for all
> sorts of reasons. semiconductors can fail, as I said in my original
> post, and are far more likely to do so having had 50 years of use.
>

Some of the old stuff is a lot more reliable than recent units, they
didn't penny pinch as much in those days. Semiconductors rarely fail if
used withing their design limits, they do fail in cheap crap where cost
are cut by running components outside their design specs.

[Mighty Mouse]

Keithr0 wrote:
> On 22/02/2024 11:52 am, Mighty Mouse wrote:
>> Keithr0 wrote:
>>> On 19/02/2024 9:57 pm, Mighty Mouse wrote:
>>>
>>>>>> not a good idea buying 40 or 50 year old electronic equipment,
>>>>>> lol. but his budget is too low for a decent HiFi sound system new.
>>>>>
>>>>> The electrolytic capacitors would be suspect, but the rest should
>>>>> be OK if it has been kept in a reasonable environment, and not
>>>>> abused.
>>>>
>>>> not necessarily. with the repetitive cycle of heating and cooling
>>>> from use dry joints develop, semiconductors fail, corrosion on
>>>> contacts, etc., and amps that old have mechanical controls. the
>>>> tracks wear on the pots and the shaft lube dries out. lots of things.
>>>
>>> Pots are easy to check, just wind them from end to end and listen
>>> for crackles, replacement is a minor job.
>>
>> but who is going to buy an amp that needs to have the pots replaced,
>> unless they're an electronics technical person who can do it
>> themselves, which noddy is not, as he has amply shown in this ng.
>> also, the person selling the amp may have just squirted the pots to
>> keep them going ok for a while.
>
> Any tech that charges more than half an hour to replace a pot is
> ripping you off. More than one pot, add 10 minutes would be more than
> adequate. Cost of a new pot ~$2. Worthwhile if it is good gear at a
> reasonable price.

that's easy to claim, not so easy to substantiate. some pots can require
significant dismantling to remove them. and some pots are unique, which
means you can't just jam any pot in there, and so they can be quite costly.

>
>>> Corrosion on contacts will not occur if it has been kept in a
>>> reasonable environment.
>>
>> which many are not, or maybe used in high humidity locations.
>
> If it's not a bottom feeding el cheapo device the plating should
> handle most indoor environments.
>
>>> Dry joints do not develop, they exist from poor soldering, broken
>>> joints can occur from heat cycling in badly designed or constructed
>>> equipment, but a good thump will usually detect it.
>>
>> IOW dry joints develop over time, as I said. you could buy an amp
>> that works fine when you purchase it, then dry joints appear some
>> time later in normal use
>
> A dry joint is a solder joint not properly done in the first place.
>
> https://www.nextpcb.com/blog/dry-solder-joint
>
> They are rare on PCBs which, these days, are usually soldered
> automatically. They are usually caused by too low a soldering iron
> temperature, not enough flux, or most likely by trying to solder to a
> contaminated surface or component.

yes, I know but solder joints that fail, for whatever reason, are called
dry joints.

>
>>> The thing is to check it before buying or get someone who knows what
>>> they are doing to check it for you.
>>
>> that will not necessarily guarantee you won't have trouble with it
>> later. amps made in the 70's or 80's are now 50 odd years old! who in
>> their right mind would buy a 50 year old amp and expect to have no
>> problems with it, especially when amps only a few years old fail for
>> all sorts of reasons. semiconductors can fail, as I said in my
>> original post, and are far more likely to do so having had 50 years
>> of use.
>>
> Some of the old stuff is a lot more reliable than recent units, they
> didn't penny pinch as much in those days.

yes. but I wouldn't recommend anyone buy equipment 50 years old, as
noddy was asking about

> Semiconductors rarely fail if used withing their design limits, they
> do fail in cheap crap where cost are cut by running components outside
> their design specs.

or often due to poor circuit design.

[Trevor Wilson]

On 22/02/2024 10:43 am, Keithr0 wrote:
> On 19/02/2024 9:57 pm, Mighty Mouse wrote:
>
>>>> not a good idea buying 40 or 50 year old electronic equipment, lol.
>>>> but his budget is too low for a decent HiFi sound system new.
>>>
>>> The electrolytic capacitors would be suspect, but the rest should be
>>> OK if it has been kept in a reasonable environment, and not abused.
>>
>> not necessarily. with the repetitive cycle of heating and cooling from
>> use dry joints develop, semiconductors fail, corrosion on contacts,
>> etc., and amps that old have mechanical controls. the tracks wear on
>> the pots and the shaft lube dries out. lots of things.
>
> Pots are easy to check, just wind them from end to end and listen for
> crackles, replacement is a minor job.

**It MAY be an easy job. Or not. It depends on the amp. Additionally and
more seriously, is if the pots are still available. Substituting pots is
often quite difficult. Some modern amps use very high quality pots,
using plastic tracks. IME, they can last a VERY long time. That said,
the cost to the manufacturer of such a pot is in the order of US$20.00
or so. A low cost pot can cost US$0.20. Guess which one is most often
chosen? These are the ones I have in my (pre)amp:

https://au.rs-online.com/web/p/potentiometers/2346617?cm_mmc=AU-PLA-DS3A-_-google-_-PLA_AU_Pmax_LocalStock_0923-_--_-&matchtype=&&gad_source=1&gclid=EAIaIQobChMIuNTygvi9hAMVMKlmAh174Qc2EAQYBiABEgIEXvD_BwE&gclsrc=aw.ds

Corrosion on contacts will not
> occur if it has been kept in a reasonable environment.

**Only if the switch contacts are gold plated. Otherwise, they will
suffer, regardless of the environment.

Dry joints do not
> develop, they exist from poor soldering, broken joints can occur from
> heat cycling in badly designed or constructed equipment, but a good
> thump will usually detect it.

**Yep.

>
> The thing is to check it before buying or get someone who knows what
> they are doing to check it for you.

**Obviously.

[Trevor Wilson]

On 22/02/2024 1:13 pm, Keithr0 wrote:
> On 22/02/2024 11:52 am, Mighty Mouse wrote:
>> Keithr0 wrote:
>>> On 19/02/2024 9:57 pm, Mighty Mouse wrote:
>>>
>>>>>> not a good idea buying 40 or 50 year old electronic equipment,
>>>>>> lol. but his budget is too low for a decent HiFi sound system new.
>>>>>
>>>>> The electrolytic capacitors would be suspect, but the rest should
>>>>> be OK if it has been kept in a reasonable environment, and not abused.
>>>>
>>>> not necessarily. with the repetitive cycle of heating and cooling
>>>> from use dry joints develop, semiconductors fail, corrosion on
>>>> contacts, etc., and amps that old have mechanical controls. the
>>>> tracks wear on the pots and the shaft lube dries out. lots of things.
>>>
>>> Pots are easy to check, just wind them from end to end and listen for
>>> crackles, replacement is a minor job.
>>
>> but who is going to buy an amp that needs to have the pots replaced,
>> unless they're an electronics technical person who can do it
>> themselves, which noddy is not, as he has amply shown in this ng.
>> also, the person selling the amp may have just squirted the pots to
>> keep them going ok for a while.
>
> Any tech that charges more than half an hour to replace a pot is ripping
> you off. More than one pot, add 10 minutes would be more than adequate.
> Cost of a new pot ~$2. Worthwhile if it is good gear at a reasonable price.

**That would be a gross over-simplification. Some pots cost more. MUCH
more. Some pots are VERY difficult to change. Most pots in equipment
that is more than (say) 15 years old, are NLA. Cleaning may be the only
solution.

>
>>> Corrosion on contacts will not occur if it has been kept in a
>>> reasonable environment.
>>
>> which many are not, or maybe used in high humidity locations.
>
> If it's not a bottom feeding el cheapo device the plating should handle
> most indoor environments.

**Trust me: It doesn't.

>
>>> Dry joints do not develop, they exist from poor soldering, broken
>>> joints can occur from heat cycling in badly designed or constructed
>>> equipment, but a good thump will usually detect it.
>>
>> IOW dry joints develop over time, as I said. you could buy an amp that
>> works fine when you purchase it, then dry joints appear some time
>> later in normal use
>
> A dry joint is a solder joint not properly done in the first place.

**A solder joint that has been subject to long-term high temperatures
(ca. 150 degrees C) can fail, despite the joint being done correctly.

>
> https://www.nextpcb.com/blog/dry-solder-joint
>
> They are rare on PCBs which, these days, are usually soldered
> automatically. They are usually caused by too low a soldering iron
> temperature, not enough flux, or most likely by trying to solder to a
> contaminated surface or component.
>
>>> The thing is to check it before buying or get someone who knows what
>>> they are doing to check it for you.
>>
>> that will not necessarily guarantee you won't have trouble with it
>> later. amps made in the 70's or 80's are now 50 odd years old! who in
>> their right mind would buy a 50 year old amp and expect to have no
>> problems with it, especially when amps only a few years old fail for
>> all sorts of reasons. semiconductors can fail, as I said in my
>> original post, and are far more likely to do so having had 50 years of
>> use.
>>
> Some of the old stuff is a lot more reliable than recent units, they
> didn't penny pinch as much in those days. Semiconductors rarely fail if
> used withing their design limits, they do fail in cheap crap where cost
> are cut by running components outside their design specs.

**Yes and, no. Electrolytic capacitors aside, plastic pack transistors
used in 1970s vintage equipment frequently fail. By the early 1980s,
transistor manufacturers had learned how to make reliable plastic pack
transistors. That said, many quality manufacturers used metal can
transistors during the 1970s. Those devices are likely to outlast our Sun.

Modern manufacturers of quality equipment tend not to penny-pinch.
Budget manufacturers do what they have always done - penny-pench.

[Mighty Mouse]

Trevor Wilson wrote:
> On 22/02/2024 10:43 am, Keithr0 wrote:
>> On 19/02/2024 9:57 pm, Mighty Mouse wrote:
>>
>>>>> not a good idea buying 40 or 50 year old electronic equipment,
>>>>> lol. but his budget is too low for a decent HiFi sound system new.
>>>>
>>>> The electrolytic capacitors would be suspect, but the rest should
>>>> be OK if it has been kept in a reasonable environment, and not abused.
>>>
>>> not necessarily. with the repetitive cycle of heating and cooling
>>> from use dry joints develop, semiconductors fail, corrosion on
>>> contacts, etc., and amps that old have mechanical controls. the
>>> tracks wear on the pots and the shaft lube dries out. lots of things.
>>
>> Pots are easy to check, just wind them from end to end and listen for
>> crackles, replacement is a minor job.
>
> **It MAY be an easy job. Or not. It depends on the amp. Additionally
> and more seriously, is if the pots are still available. Substituting
> pots is often quite difficult.

yep

> Some modern amps use very high quality pots, using plastic tracks.
> IME, they can last a VERY long time. That said, the cost to the
> manufacturer of such a pot is in the order of US$20.00 or so. A low
> cost pot can cost US$0.20. Guess which one is most often chosen? These
> are the ones I have in my (pre)amp:
>
> https://au.rs-online.com/web/p/potentiometers/2346617?cm_mmc=AU-PLA-DS3A-_-google-_-PLA_AU_Pmax_LocalStock_0923-_--_-&matchtype=&&gad_source=1&gclid=EAIaIQobChMIuNTygvi9hAMVMKlmAh174Qc2EAQYBiABEgIEXvD_BwE&gclsrc=aw.ds
>
>
>>
>>  Corrosion on contacts will not occur if it has been kept in a
>> reasonable environment.
>
> **Only if the switch contacts are gold plated. Otherwise, they will
> suffer, regardless of the environment.

exactly

>
>
>>  Dry joints do not develop, they exist from poor soldering, broken
>> joints can occur from heat cycling in badly designed or constructed
>> equipment, but a good thump will usually detect it.
>
> **Yep.

poor soldering is the cause of dry joints, but there's no dry joint
until the joint fails. while there's still conductivity it's not a dry
joint.

>
>>
>> The thing is to check it before buying or get someone who knows what
>> they are doing to check it for you.
>
> **Obviously.
>
>


--

Have a nice day!..

[Trevor Wilson]

**I've seen a variety of dry joints that have lasted for decades. Until
they don't. Usually, it's due to a contaminant on the lead/s of a device
and the solder does not properly 'wet' the joint. As I stated,
sometimes, the device can function normally for many years and then the
corrosion finally causes a failure. Usually though, it's due to
vibration or high temperatures that causes a gradual failure of the
joint. 150 degrees C over a decade or so will cause damage to most
solder joints.

[Xeno]

Seem them fail in high frequency environments too. Basically a form of
fatigue failure.

Xeno

Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)