The Dick smith A-2760 Amp
Unknown
After seeing several favourable comments re the DSE A2760 80W RMS amp
on this group recently, and being in the market for a good,
inexpensive unit, I just had to go and check this one out.
The local DSE stockist had one setup in their "sound lounge" and
after a quick test drive I was very impressed with it, took the plunge
and bought one.
Especially at the price of $129 (locally) you can't go wrong !
There isn't a lot of info on it on the DSE website - but in brief it
has got bass/treble/balance controls (the knobs are rather small in
the DSE web pic and look more like pushbuttons), has a tone bypass
switch, 4 line level inputs, and a tape output. Unit however doesn't
have a phono input, so this may be a bit of a problem for vinyl
enthusiasts.
Anyway - for those who are interested on what it looks like inside - I
took the top off it and put some pics up for those in the group who
might want to see the internals, general construction and layout.
http://www.geocities.com/kenreed1999/DickAmpFR.jpg
http://www.geocities.com/kenreed1999/DickAmpPC.jpg
http://www.geocities.com/kenreed1999/DickAmpR.jpg
http://www.geocities.com/kenreed1999/DickAmpTOP.jpg
Phil Allison
<KLR> wrote in message news:k2eg90t9cge8aj04k...@4ax.com...
>
> Anyway - for those who are interested on what it looks like inside - I
> took the top off it and put some pics up for those in the group who
> might want to see the internals, general construction and layout.
>
> http://www.geocities.com/kenreed1999/DickAmpFR.jpg
> http://www.geocities.com/kenreed1999/DickAmpPC.jpg
> http://www.geocities.com/kenreed1999/DickAmpR.jpg
> http://www.geocities.com/kenreed1999/DickAmpTOP.jpg
** Thanks for the cool pics !
I can see separate DC supplies are used for each power channel (tranny
windings, rectifiers and filter caps ) and the same for the +/- regulators
in the pre-amp section. Also there are very hefty looking output
transistors and independent speaker relays for anti-thump and DC protection.
The el-cheapo volume pot is a bit sad - but it looks possible to
upgrade that to a cermet track one with a bit of effort.
BTW Don't ya just love the toroidal with " POWER TRANSFORMER " written
on it !!
The amp has no ground wire in the AC lead ( ie it is supposedly double
insulated) which is unusual for items fitted with a toroidal power
transformer.
I hope the Chinese have not fudged the safety issue.
.......... Phil
Dale
"Phil Allison" <phila...@optusnet.com.au> wrote in message
news:409844ba$0$30603$afc3...@news.optusnet.com.au...
Great pic's and description guy's
Thanks
Dale
Mark Hathaway
they use the non toxic variety for the poor kid in the factories sake
Mark
"Dale" <dpoole@iinetdotnetdotau> wrote in message
news:409848de$0$16598$5a62...@freenews.iinet.net.au...
Steve Robertson
>Love the heatsink compound fingerptrints all over the output devices. hope
>they use the non toxic variety for the poor kid in the factories sake
>
Just how toxic is silicon? heatsink compound
Absorbed through the skin or do you you have to eat it??
(Im working with the stuff rebuliding laser printer fusers)
Steve Robertson
Separate power supplies(almost).
Proper binding posts, no spring clip connectors
Watch that skin effect on banana plugs
banana, skin..... oh well .......
Phil Allison
"Steve Robertson" <nos...@nospam.com>
"Mark Hathaway" <markhathaw...@bigblue.net.au> wrote:
>>
> >Love the heatsink compound fingerptrints all over the output devices.
hope
> >they use the non toxic variety for the poor kid in the factories sake
> >
>
> Just how toxic is silicon? heatsink compound
** It is not the least toxic - it is a mixture of silicone grease (
widely used in industry for lubricating bearings) and zinc oxide - widely
used as a sun block on kid's noses.
Mark's smart remark was very mischievous - he was alluding to the use of
beryllium oxide in lieu of zinc oxide as a filler in the grease, something
not done for many decades.
.............. Phil
Mark Harriss
I was under the impression it was still used today for some components
Steve Batt
"Mark Harriss" <ni...@nong.com> wrote in message
news:4098...@news.comindico.com.au...
It is, we use it at work
Steve
>
Phil Allison
"Steve Batt" <s_j_...@bigpond.net.au>
> "Mark Harriss" <ni...@nong.com> wrote in message
> >
> > I was under the impression it was still used today for some
> components
>
> It is, we use it at work
** Please give details - what beryllium oxide loaded thermal grease
product obtained from whom.
.............. Phil
matrokr
sounds interesting... but can't see your pix - any idea why?
Mark Harriss
Componentwise: just about any non russian (They have pink manganese
based ceramic) made 3/4/5CX series ceramic valve and quite a few of those
white ceramic RF transistors and certain mil spec IC packages to name a few
items. High temp high vacuum electric feedthroughs. It's reasonably
conductive of heat as well as being capable of withstanding high
temperatures for a ceramic. I was using BeO thermal paste for Navy
applications in 1998 as that was specified by them, don't know if they use
it still.
Before you respond Phil, you'll note that I qualified that paragraph
"componentwise"/.
regards
Mark H
Phil Allison
"Mark Harriss" <ni...@nong.com>
> Phil Allison wrote:
> >
> > ** Please give details - what beryllium oxide loaded thermal
grease
> > product obtained from whom.
>
> Componentwise:
** Not relevant to the question - dickhead.
Solid objects made form BeO are not a hazard.
.............. Phil
Mark Harriss
Ahh yes..... when wrong...attack!!!!!. Also if you'd bothered
to peruse any MSDS on BeO you'd realise how wrong you are:
Contact with solid beryllia can result in an acute skin reaction.
kind regards
Mark H
Phil Allison
"Mark Harriss" <ni...@nong.com> >
> >
>> >> Phil Allison wrote:
> >
> >> >
> >> > ** Please give details - what beryllium oxide loaded thermal
> > grease product obtained from whom.
> >
> >
> >>
> >> Componentwise:
> >
> >
> > ** Not relevant to the question - dickhead.
> >
> > Solid objects made form BeO are not a hazard.
> >
>
>
> Ahh yes..... when wrong...attack!!!!!.
** That must be your motto - fuckhead.
> Also if you'd bothered to peruse any MSDS on BeO you'd realise how wrong
you are:
** I am not wrong.
> Contact with solid beryllia can result in an acute skin reaction.
** Bullshit.
............... Phil
Steve Batt
Sorry Phil, thats classified under the official secrets act.
Steve
>
>
Steve Batt
They are when they break
Steve
>
>
>
Arny Krueger
I did the recommended exercise - looked at safety documents relevant to BeO.
It turns out that the danger from BeO relates to breathing the dust. The
finished BeO objects are dust-free for obvious reasons, but breaking BeO
objects can relase some BeO dust. Obviously, BeO grease is not breathed.
Anubis
Steve Batt
"Anubis" <Osi...@Isis.com> wrote in message
news:e1r1qr7b6as01vk.060520042111@Luxor...
>
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Phil Allison
"Arny Krueger" <ar...@hotpop.com
> I did the recommended exercise - looked at safety documents relevant to
BeO.
>
> It turns out that the danger from BeO relates to breathing the dust. The
> finished BeO objects are dust-free for obvious reasons, but breaking BeO
> objects can relase some BeO dust.
> Obviously, BeO grease is not breathed.
** BeO particles are also a hazard if contacted by the skin - since it is
not only a allergen but a toxin and a carcinogen ( with no safe exposure
level !!!!!!! ).
Handling silicon grease filled with BeO dust would, after basic cleansing,
leave BeO particles embedded in any tiny cracks and scratches in the
in - so not it is not safe to use without gloves.
Possibly much worse is the fact that silicon grease evaporates over time so
when used as a semiconductor heatsink compound the BeO particles are
eventually released as dust again - especially if disturbed after some
years.
The most likely victim of such particles is repair techs working on old
amplifiers.
Now who would that be ???????????????
............ Phil
Phil Allison
"Anubis" <Osi...@Isis.com>
> Problem solved! You can tell him, but then you have to kill him...
>
** Whadaya mean - problem solved ?????????
I'm just dying to know !!
.............. Phil
Anubis
Can you put that in writing, witnessed by someone over the age of 18 years,
please. (That will make it fatal to any argument about the matter, and a
mortal blow to the contrary. It will bury the opposition, who will be
dead in the water.)
Belial
>
> After seeing several favourable comments re the DSE A2760 80W RMS amp
> on this group recently, and being in the market for a good,
> inexpensive unit, I just had to go and check this one out.
<snip>
Thanks for the pics.
There was a discussion about this weeks (months?) ago where I mentioned a
review I'd read in a forum. Unfortuantely my PC went splat and I never got
to post the details. You need to sign up for to view the forums, so I'll
post the text here and links to the pics. There's an 11 or so page thread
discussing the amp (and various kinda related stuff).
Link to the specific post: http://forums.overclockers.com.au
showthread.php?s=&postid=2840210#post2840210
Post by Volenti.
<quote>
Ok I've subjected the amp to some testing, just objective measurements for
the moment.
The setup;
Pic: http://users.bigpond.net.au/volenti/DSE_amp_test.jpg
The volunteer, a sine wave generator, a bank of 4 ohm 100w test loads, and
a digtial scope.
8 ohm load per channel first;
Pic : http://users.bigpond.net.au/volenti/DSE_amp_8ohm.jpg
slightly under the 80w rated power at 74w/ch but if I pushed it into 1%
distortion it hit 80w.
Now for a 4 ohm load per channel;
Pic : http://users.bigpond.net.au/volenti/DSE_amp_4ohm.jpg
well well, 125W/ch (at 1%distortion, ~120w clean) very nice.
I used 100hz for the test, but also tried 20hz, 1k, and 10k with similar
results.
now for the frequency response I used my Coustic RTA which has a built in
pink noise generator and the capability to directly accept high level
inputs, results;
Pic: http://users.bigpond.net.au/volenti/DSE_amp_response.jpg
flat as a board, can't really argue with that I had the tone control set
to off since the bass and treble had no center indents.
I took a massive pic of the insise of the amp, which I'll only link to
since it's half a meg and would break the forum template.
very big pic : http://users.bigpond.net.au/volenti/DSE_amp_inside.jpg
I've circled and labeled the signal cables that you need to change to
either convert the amp into a slave or run it as a slave off another DSE
amp.
A and B are Right and Left signal output from the input selecter.
E and F are Right and Left signal input on the pre-amp.
G and H are Right and Left signal output from the pre-amp.
C and D are Right and Left signal input on the amp board.
To turn this into a traditional slave amp, ie an amp with just an ON
button, un-plug E,F,C and D. The plugs that you pulled out of E and F you
plug into positions C and D, so you end up with a cable connecting A to C
and another connecting B to D, don't worry about the other 2 un-used plugs,
just tie them up somewhere.
The input selector will still work on the slave amp with this setup.
Here's a pic of what it should look like;
Pic: http://users.bigpond.net.au/volenti/DSE_amp_slave.jpg
</quote>
Ben
matrokr
thanks; cutting and pasting into a new window did the trick.
the components looking pretty good for the price... reminds me of the price-performance
quality of shinco dvd players
KLR <> wrote:
>On Thu, 06 May 2004 05:18:52 GMT, "matrokr"
><mat...@nospamr.velnet.com.au> wrote:
>
>>
>>sounds interesting... but can't see your pix - any idea why?
>>
>--------------------------------------------------
>
>working fine here
>
>you might want to keep trying every so often - as they have a limit on
>how many hits (MB) in an hour or something like that.
>
>cutting and pasting the links into the browser may help - as in some
>cases if you click on a link (from ebay site for example) - the
>geocities pages wont open often.
>
>----------------------------------------------------
Arny Krueger
> "Arny Krueger" <ar...@hotpop.com
>
>> I did the recommended exercise - looked at safety documents relevant
>> to BeO.
>>
>> It turns out that the danger from BeO relates to breathing the dust.
>> The finished BeO objects are dust-free for obvious reasons, but
>> breaking BeO objects can relase some BeO dust.
>
>> Obviously, BeO grease is not breathed.
>
>
> ** BeO particles are also a hazard if contacted by the skin -
> since it is not only a allergen but a toxin and a carcinogen ( with
> no safe exposure level !!!!!!! )
Right, particles as in BeO powder.
> Handling silicon grease filled with BeO dust would, after basic
> cleansing, leave BeO particles embedded in any tiny cracks and
> scratches in the in - so not it is not safe to use without gloves.
Yes, that clearly happens with heat sink grease that is filled with
thermally conductive powder.
> Possibly much worse is the fact that silicon grease evaporates over
> time so when used as a semiconductor heatsink compound the BeO
> particles are eventually released as dust again - especially if
> disturbed after some years.
That I haven't seen
> The most likely victim of such particles is repair techs working on
> old amplifiers.
> Now who would that be ???????????????
You?
Looking at the literature, it appears that Aluminum Nitride costs a little
more, but is a safer replacement for BeO.
This begs the question how you can tell what you are working with on any
particular day?
I guess the answer is gloves, regardless.
>
>
>
>
> ............ Phil
Phil Allison
"Arny Krueger" <ar...@hotpop.com>
>
> Phil Allison wrote:
>
> > Possibly much worse is the fact that silicon grease evaporates over
> > time so when used as a semiconductor heatsink compound the BeO
> > particles are eventually released as dust again - especially if
> > disturbed after some years.
>
** You have not seen old silicone based thermal compound dry completely out
??? You have never had to scrape the chalky residue off of a heatsink after
removing a TO3 pack semi ???
Dear Arny - lemme tell ya , you have just not lived !!!
>
> > The most likely victim of such particles is repair techs working on
> > old amplifiers.
>
> > Now who would that be ???????????????
>
> You?
** What insight ;-)
>
> Looking at the literature, it appears that Aluminum Nitride costs a little
> more, but is a safer replacement for BeO.
>
** Thermal grease makers ( much like snake oil merchants) are reluctant
to reveal their dark secrets - but I was under the distinct impression
that zinc oxide was the cheapest and hence favourite silicone grease filler.
> This begs the question how you can tell what you are working with on any
> particular day?
>
** Absobloomimlutelty !!!
That is WHY I want ***evidence** of who is allegedly still selling the
dangerous, filthy BeO filled stuff !!!
............... Phil
Dale
"Belial" <m...@privacy.net> wrote in message
news:2fup6pF...@uni-berlin.de...
Great post Ben,
Thanks.
Dale
Dale
"Tat Chan" <le_kin...@hotmail.com> wrote in message
news:2g0a3pF...@uni-berlin.de...
> Dale wrote:
>
> <objective measurements info snipped>
>
> >
> >
> > Great post Ben,
> >
> > Thanks.
> >
> > Dale
> >
> >
>
>
> where are the obligatory review quotes like
>
> "fast, lucid bass"
> "transparent imaging"
> "can match amps costing up to 3 times the price"
> "has the boogie factor"
> "the mid range has an airy quality"
> "5 stars"
>
> sheesh, next thing you know, we'll all be swapping National
> Semiconductors spec sheets!
>
> :P
Or power curves A la RAT's :-)
Dale
Mark Hathaway
Some of the silver oxide thermal compounds are still dangerous, while not
being a carcinogenic and nowhere near as bad as beryllium, extendued use
(like being the sucker who mounts devices to heatsinks all day everyday) can
be dangerous, and score a Hazard flag on the MSDS for the NFPA and HMIS
tests
Mark
"Phil Allison" <phila...@optusnet.com.au> wrote in message
news:40989650$0$20347$afc3...@news.optusnet.com.au...
Steve Robertson
>haha, didn't mean to cause such a fuss.
>Some of the silver oxide thermal compounds are still dangerous, while not
>being a carcinogenic and nowhere near as bad as beryllium, extendued use
>(like being the sucker who mounts devices to heatsinks all day everyday) can
>be dangerous, and score a Hazard flag on the MSDS for the NFPA and HMIS
>tests
>
Getting back to my original post
Im using using the (Chinese)white stuff & having to clean off the old white
stuff: any (Real) possible hazards (death, cancer)
Do you need to eat it or is skin contact hazardous.
Or is it more than likely just Zinc based (saving me money on Oysters)
Phil Allison
"Steve Robertson" <nos...@nospam.com> wrote in message
news:409c29fc$1...@clear.net.nz...
>
> Getting back to my original post
> Im using using the (Chinese)white stuff & having to clean off the old
white
> stuff: any (Real) possible hazards (death, cancer)
> Do you need to eat it or is skin contact hazardous.
> Or is it more than likely just Zinc based (saving me money on Oysters)
** So far *** no-one*** can tell us the name of any supplier of
beryllium oxide filled thermal grease - looks like it is certainly rare
stuff.
If you bothered to read the thread all your questions are already
answered.
............ Phil
Steve Batt
Don't Panic
Steve
Phil Allison
"Steve Batt" <s_j_...@bigpond.net.au>
> Don't Panic
>
> Steve
>
** So is the "cure" for beryllium poisoning beer and crisps ???
................. Phil
Steve Batt
Steve
Steve Robertson
>>
>> ** So is the "cure" for beryllium poisoning beer and crisps ???
>>
>no, beer and peanuts
>
This is great. I can justify going to the pub at lunchtime for my cure
And the boss will have to pay for it.
Arny Krueger
> Getting back to my original post
> Im using using the (Chinese)white stuff & having to clean off the old
> white stuff: any (Real) possible hazards (death, cancer)
Just because it's Chinese tells us nothing about its actual chemical
composition.
> Do you need to eat it or is skin contact hazardous.
Skin contact can be all it takes.
> Or is it more than likely just Zinc based (saving me money on Oysters)
It might be zinc based, or not.
One small brief contact won't kill you, but might it trigger an allergic
reaction.
Steve Batt
Yes, but your house might get demolished while you're at the pub, and you'll
need 3 pints.
Remember, Don't panic
Steve
Adam F
"Dale" <dpoole@iinetdotnetdotau> wrote in message
news:409afb75$0$16583$5a62...@freenews.iinet.net.au...
>
>
> Or power curves A la RAT's :-)
>
> Dale
>
>
Hehe RAT is all about fast, airy openness with a liquid quality common to
all XXX designs if you ask me ;)
Speaker impedance curves are an important consideration for that crowd
tho....
Adam F
paul packer
I wonder if anyone's tried to add a headphone socket to this amp, and
if so what value resistors would be used. I'd like to get the amp,
especially at the current $128, but I mostly use headphones.