Vox AC30 issue on/off and standby
RichL
switches. It's intermittent and has appeared in a number of forms:
1. Power on switch turned on, light doesn't come on. Tubes don't warm
up.
2. Power on switch turned on, light comes on momentarily but then turns
right back off.
3. Power on switch turned on, light comes on but only after about 10
seconds. After letting it warm up and flipping the standby switch,
everything seems fine.
4. Power on switch on, light comes on fine, tubes warm up, but when I
switch the standby, everything shuts off.
5. One time I powered it up but neglected to have the volume for the
channel I was using turned down. When I flipped the standby, the amp
made a horrible farting noise and then shut down.
In between these events, the amp works fine. But they're becoming
increasingly frequent.
Any ideas on what's causing this? Thanks in advance!
Claude V. Lucas
How often do you play it?
When was the last time it was in for a pro checkup by someone
who understands the AC30?
Longer than 5 years, less if it mainly sits?
Short answer, take it in.
I repeat myself, but "someone who understands the AC30" is key.
Gary Gerhart
Lucas, The Prince of Darkness...
Oh, wait. It's British but *not* a Jag...
Try a new power switch.
Gary Gerhart
Gerhart Amplification
Claude V. Lucas
RichL
> In article <EdSdnZ6XWN9HZTPU...@supernews.com>,
> RichL <rple...@yahoo.com> wrote:
>> I've got an old top-boost AC30 with issues with the on/off and
>> standby switches. It's intermittent and has appeared in a number of
>> forms:
>>
>> 1. Power on switch turned on, light doesn't come on. Tubes don't
>> warm up.
>>
>> 2. Power on switch turned on, light comes on momentarily but then
>> turns right back off.
>>
>> 3. Power on switch turned on, light comes on but only after about 10
>> seconds. After letting it warm up and flipping the standby switch,
>> everything seems fine.
>>
>> 4. Power on switch on, light comes on fine, tubes warm up, but when
>> I switch the standby, everything shuts off.
>>
>> 5. One time I powered it up but neglected to have the volume for the
>> channel I was using turned down. When I flipped the standby, the amp
>> made a horrible farting noise and then shut down.
>>
>> In between these events, the amp works fine. But they're becoming
>> increasingly frequent.
>>
>> Any ideas on what's causing this? Thanks in advance!
>
> How often do you play it?
Two or three times a week, on average. It's my most-used amp.
> When was the last time it was in for a pro checkup by someone
> who understands the AC30?
Took it in less than 2 years ago, and then 2 years before that. Two
different techs, but whether either is "someone who understands the
AC30" is questionable.
> Longer than 5 years, less if it mainly sits?
>
> Short answer, take it in.
>
> I repeat myself, but "someone who understands the AC30" is key.
Yeah, I think I've identified a guy who fits the bill. Thanks, I was
hoping this was a simple fix and I could avoid the hassle.
Phil S.
"Gary Gerhart" <Ga...@GerhartAmps.com> wrote in message
news:6aDrl.19234$c45....@nlpi065.nbdc.sbc.com...
And if that doesn't work, see if you can get Jeff Bober/Precision Audio
Tailoring (also of Budda Amp fame) to take it in. Google for Precision
Audio Tailoring and you'll get a pile of hits. He's in Halethorpe. Jeff is
typically too busy for everyone. On the up side, he's a heck of alot better
than "just barely competent". You might also call Phil Jacoby for a
recommendation.
Phil
WB
>
> Any ideas on what's causing this? Thanks in advance!
>
>
I'm going to go *WAY* out on a limb here and
REPLACE THE *SWITCH*.
Look for loose connections too .. rectifier tube .. if there is one.
YMMV
WB
> Oh, wait. It's British
>
>
Huh ! Follow the oil leak !
RichL
> RichL wrote:
>>
>> Any ideas on what's causing this? Thanks in advance!
>>
>>
>
> I'm going to go *WAY* out on a limb here and
>
> REPLACE THE *SWITCH*.
That would make sense except for observation #4 above. Why would
flipping the standby switch cause the whole amp to shut down? At this
point the on/off switch is "on" and the red light is lit, until I flip
the standby switch (a separate entity) to the "on" position, at which
point the red light goes off.
You may be right, and I'll try some deoxit on both switches just in case
that provides a quick fix.
> Look for loose connections too .. rectifier tube .. if there is
> one.
SS rectifier....
RichL
Phil has suggested Pete Cage in Damascus previously, who is also one of
the folks listed on AGA's web site. I think I'll give him a try first.
TD Madden
Gary Gerhart
> WB <war...@ppp.com> wrote:
>> RichL wrote:
>>> Any ideas on what's causing this? Thanks in advance!
>>>
>>>
>> I'm going to go *WAY* out on a limb here and
>>
>> REPLACE THE *SWITCH*.
>
> That would make sense except for observation #4 above. Why would
> flipping the standby switch cause the whole amp to shut down? At this
> point the on/off switch is "on" and the red light is lit, until I flip
> the standby switch (a separate entity) to the "on" position, at which
> point the red light goes off.
But...
Isn't the standby switch right next to the power switch?
Mechanical shock, and so forth
Gary Gerhart
Gerhart Amplification
Gary Gerhart
Ah,
So you too have owned a Jag...
Gary Gerhart
Gerhart Amplification
Gary Gerhart
SS recto...
Is it a Rose Morris?
Gary Gerhart
Gerhart Amplification
RichL
As near as I can tell from both the appearance and the schematic (I
bought it used), it's a 1990 top-boost standard model. Here's the
schematic:
http://www.schematicheaven.com/voxamps/ac301990.pdf
So yeah, it's one of the later Morris models.
WB
>>>
>> I'm going to go *WAY* out on a limb here and
>>
>> REPLACE THE *SWITCH*.
>
> That would make sense except for observation #4 above. Why would
> flipping the standby switch cause the whole amp to shut down?
>
Grass hopper .. When you can snatch the flicking glow
out of the rear of the amp without getting shocked ...
... You will know the answer.
IOW: Inspect, tighten, clean, repair, replace the whole bloody bastard !
RichL
Well I'm no amp tech, not even a pretend one. I'm convinced that it's
the on/off switch. Simple enough, right? But there's also an issue of
the vibrato channel leaking into the other ones that needs to be dealt
with, so it's off to the tech. Kill two birds with one stone.
p.s...It completely bit the dust this afternoon. No amount of fooling
with the switch would make it come on.
jh
Hi Rich,
my bet is a broken wire or a cold solder joint at either
the mains (somewhere between the power switch an the voltage selector)
or IMHO even more likely a cold solder joint at the point at the heater
string, possibly at the power light, where it is distributed.
my cts
regards
Jochen
libsni...@gmail.com
Take off the cover while you're playing it and wiggle and touch any
and all wires and parts etc. until you hear a sound.
WB
>>
>> IOW: Inspect, tighten, clean, repair, replace the whole bloody
>> bastard !
>
> Well I'm no amp tech, not even a pretend one. I'm convinced that it's
> the on/off switch. Simple enough, right? But there's also an issue of
> the vibrato channel leaking into the other ones that needs to be dealt
> with, so it's off to the tech. Kill two birds with one stone.
>
>
>
Jim
You shouldn't even joke around like that. Could be a kid watching, and
willing to try all suggestions.
NEVER open a tube amp chassis unless you understand all safety
precautions, including the fact that some amps can store enough energy
in their filter capacitors, even when turned off and unplugged, to ruin
your day (or worse).
Jim
Sounds like it's on the primary side of the PT. Bad switch, issue with
the fuse, bad solder around the switches...
On my Twin rebuild, the standby switch was microphonic, but not the
tubes. I replaced it, no help. I tapped the chassis in that area,
microphonic! Cleaned up chassis connections and tightened everything.
Still a problem. It turned out to be a bad choke with partial short to
ground. Any mechanical shock, like flicking the switch, would affect it.
Angus Manwaring
Sounds like very good advice to me, I've had my AC30 looked at my many
skilled Electronic Engineers, but it took a knowlegable music amp
specialist to get it playing better than ever.
But Rich, the standby thing is a mod? Or do we use the term "old"
differently? :)
All the best,
Angus Manwaring. (for e-mail remove ANTISPEM)
I need your memories for the Amiga Games Database: A collection of Amiga
Game reviews by Amiga players http://www.angusm.demon.co.uk/AGDB/AGDB.html
TD Madden
RichL
> On 04-Mar-09 22:20:43, Claude V. Lucas said
>> In article <EdSdnZ6XWN9HZTPU...@supernews.com>,
>> RichL <rple...@yahoo.com> wrote:
>
>> Longer than 5 years, less if it mainly sits?
>
>> Short answer, take it in.
>
>> I repeat myself, but "someone who understands the AC30" is key.
>
>
> Sounds like very good advice to me, I've had my AC30 looked at my many
> skilled Electronic Engineers, but it took a knowlegable music amp
> specialist to get it playing better than ever.
>
> But Rich, the standby thing is a mod? Or do we use the term "old"
> differently? :)
It's not a mod. Near as I can figure this amp is from 1990; it's got
the standby switch, six input jacks (three channels, high and low on
each), Greenback speakers but no reverb, deep copper colored top panel.
I suppose that's not all that old.
libsni...@gmail.com
> libsnightm...@gmail.com wrote:
> > On Mar 4, 1:57 pm, "RichL" <rpleav...@yahoo.com> wrote:
> >> I've got an old top-boost AC30 with issues with the on/off and standby
> >> switches. It's intermittent and has appeared in a number of forms:
>
> >> 1. Power on switch turned on, light doesn't come on. Tubes don't warm
> >> up.
>
> >> 2. Power on switch turned on, light comes on momentarily but then turns
> >> right back off.
>
> >> 3. Power on switch turned on, light comes on but only after about 10
> >> seconds. After letting it warm up and flipping the standby switch,
> >> everything seems fine.
>
> >> 4. Power on switch on, light comes on fine, tubes warm up, but when I
> >> switch the standby, everything shuts off.
>
> >> 5. One time I powered it up but neglected to have the volume for the
> >> channel I was using turned down. When I flipped the standby, the amp
> >> made a horrible farting noise and then shut down.
>
> >> In between these events, the amp works fine. But they're becoming
> >> increasingly frequent.
>
> >> Any ideas on what's causing this? Thanks in advance!
>
> > Take off the cover while you're playing it and wiggle and touch any
> > and all wires and parts etc. until you hear a sound.
>
> You shouldn't even joke around like that. �Could be a kid watching, and
> willing to try all suggestions.
RS is the only kid in here and his mom can't afford to buy him an amp.
jh
RS
>libsni...@gmail.com schrieb:
>> On Mar 5, 10:03?am, Jim <j...@askmebeforeyousend.com> wrote:
>> RS is the only kid in here and his mom can't afford to buy him an amp.
>doubtful
LOL! Gigaboy's sense of reality is consistent anyway.
I hope this doesn't sound too odd, but I'm not sure how many amps I
have. 30 maybe? I've worked for musical instrument companies and
sometimes build them for myself, so it's easy to accumulate. And I've
compulsively picked up a bunch of old Fenders and a few Ampegs and
Marshalls.
Here's the embarrassing part though: I've got a wall stacked 2 or 3
deep in the sound room, and usually only turn on a few favorites, so I
don't look at them every day. I was talking with someone about Fender
Champ II amps (maybe that was you?), Ended up thinking that I should
get one. So...yesterday, I had to move something in the sound room,
and there was...a Champ II. Damn, I don't even remember where that
came from. That's pretty bad, eh?
Also found an extra regular Champ and a Princeton that I had forgotten
about, but I remembered those after I saw them. I thought I had given
the Princeton away.
Anyway, the Champ II did remind me of you, Jochen. Push-pull 6V6's
with your favorite...split-load PI. One extra gain stage, wired like
the reverb channel in a Fender reverb amp (2.2M resistor), but with no
reverb tank. All in all, kinda like one channel of a Princeton or
older Deluxe. More compact though, and unlike a regular Champ, it has
a 10" speaker, so there are a lot of options.
jh
Hi RS,
very nice, my score is far from 30 yet, but there are a few here also.
Mainly fender and Marshall, but also a KittyHawk and a Burman...
No it was not me with whom you talked about the champ II, haven't played
or opened up yet, but there were a few super champs; propably champ IIs
on steroids. I bet it is nice - especially with the 10".
I'm packing my 5E3 at the moment - these evening is our monthly session
time. If it's only half the fun of last month, it's going to be great...
regards
Jochen
McGarnagle
LOL
Looks like I hit a nerve.
So when we going to hear some clips?
RS
<McGar...@notospam.com> wrote:
>
>Looks like I hit a nerve.
Hardly, but keep flailing away. Amusing to think of how many hours
you spend here every day. Father MacKenzie.
>So when we going to hear some clips?
Where's yours?
Angus Manwaring
Ah okay, I ask as somebody who considered having a master volume mod
fitted to my AC30 TB, - but in the end I changed amp.
RS
wrote:
>RS schrieb:
>>
>> Anyway, the Champ II did remind me of you, Jochen. Push-pull 6V6's
>> with your favorite...split-load PI. One extra gain stage, wired like
>> the reverb channel in a Fender reverb amp (2.2M resistor), but with no
>> reverb tank. All in all, kinda like one channel of a Princeton or
>> older Deluxe. More compact though, and unlike a regular Champ, it has
>> a 10" speaker, so there are a lot of options.
>>
>Hi RS,
>
>very nice, my score is far from 30 yet,
There's time. <g> I should ditch some of mine. They can be a
distraction.
>but there are a few here also.
>Mainly fender and Marshall, but also a KittyHawk and a Burman...
I haven't had a chance to play through either KittyHawk or Burman.
I've heard some good things though. Particularly curious about the
Burman. Partridge transformers, right?
>No it was not me with whom you talked about the champ II, haven't played
>or opened up yet, but there were a few super champs; propably champ IIs
>on steroids. I bet it is nice - especially with the 10".
Yeah, the SuperChamp circuit is similar, and it has reverb. And
unfortunately uses one of those triple triodes (6C10, I think) from
color-TV era. They evidently thought it was cost-effective, as they
needed another stage for the reverb post amp. The 'mixer' stage was
already in place in the Champ II.
Personally, I would have preferred that they use a simple FET or
MosFet as reverb recovery. That would have allowed them to use a
12ax7.
The SuperChamp also omits the mid control, for some reason. Doesn't
do a whole lot in the Fender stack, but it's still better than
nothing.
>I'm packing my 5E3 at the moment - these evening is our monthly session
>time. If it's only half the fun of last month, it's going to be great...
Hope it went well, Jochen. Always nice to hear what the toys can do
when they're cranked up. Sounds like the 5E3 is still your favorite.
BTW, have you had a chance to compare the Red Fang to your Vox Blue?
jh
> On Fri, 06 Mar 2009 18:34:18 +0100, jh <jh-audio...@t-online.de>
> wrote:
>
>> RS schrieb:
>>> Anyway, the Champ II did remind me of you, Jochen. Push-pull 6V6's
>>> with your favorite...split-load PI. One extra gain stage, wired like
>>> the reverb channel in a Fender reverb amp (2.2M resistor), but with no
>>> reverb tank. All in all, kinda like one channel of a Princeton or
>>> older Deluxe. More compact though, and unlike a regular Champ, it has
>>> a 10" speaker, so there are a lot of options.
>>>
>
>> Hi RS,
>>
>> very nice, my score is far from 30 yet,
>
> There's time. <g> I should ditch some of mine. They can be a
> distraction.
>
>> but there are a few here also.
>> Mainly fender and Marshall, but also a KittyHawk and a Burman...
>
> I haven't had a chance to play through either KittyHawk or Burman.
> I've heard some good things though. Particularly curious about the
> Burman. Partridge transformers, right?
>
right, it has Partridges.
I must confess, the burman was a "never heard one, should have one,
can't try one, so buy one" ebay purchase. I'm not so much convinced
about the tone. It's "very special" and has a unique sound and handling
of the controls. I have not invested much time to try it out; it just
sits there.
>> No it was not me with whom you talked about the champ II, haven't played
>> or opened up yet, but there were a few super champs; propably champ IIs
>> on steroids. I bet it is nice - especially with the 10".
>
> Yeah, the SuperChamp circuit is similar, and it has reverb. And
> unfortunately uses one of those triple triodes (6C10, I think) from
> color-TV era. They evidently thought it was cost-effective, as they
> needed another stage for the reverb post amp. The 'mixer' stage was
> already in place in the Champ II.
>
> Personally, I would have preferred that they use a simple FET or
> MosFet as reverb recovery. That would have allowed them to use a
> 12ax7.
>
> The SuperChamp also omits the mid control, for some reason. Doesn't
> do a whole lot in the Fender stack, but it's still better than
> nothing.
>
>> I'm packing my 5E3 at the moment - these evening is our monthly session
>> time. If it's only half the fun of last month, it's going to be great...
>
> Hope it went well, Jochen. Always nice to hear what the toys can do
> when they're cranked up. Sounds like the 5E3 is still your favorite.
It's always essential to chose the right tool for the particular job.
The 5E3 is a no brainer for this kind of jam session. Club with 80-100
guests. Loud enough to cut through, not earshattering. No miking of the
amps or the drum kit at all, just the vocs and sometimes a baritone sax.
Set it and forget it. It has worked perfectly for years now and all the
players who use the amps are happy.
What's better than one 5E3 on a stage? Two 5E3s ;-))
>
> BTW, have you had a chance to compare the Red Fang to your Vox Blue?
>
No hav not manageed it yet - i had an old completely butchered "brown
super" restauration on the bench for months. It haunted me with a weird
hum on the vibrato channel.
Fortunately i found the reason on Sunday night this week - The Volume
pot was wired backwards from the factory !
Now there's a 400PS waiting and unfortunately a lot of work on my day
time job. Too many projects, too little time on my hands....
regards
Jochen
libsni...@gmail.com
> On Fri, 06 Mar 2009 19:16:45 -0800, McGarnagle
>
Bullshit.
Your world was rocked so hard you had to write your life history with
amps.
>Amusing to think of how many hours
> you spend here every day. �
...but *scary* to think of how many hours you spend stalking me here
every day.
> >So when we going to hear some clips?
>
> Where's yours?
Don't play dumb with me. You've already heard and commented on my
clips under your "V" screen name. Then you changed to "Red" and now
you're "RS", because you don't want people to know all the nerd groups
you post to...
It's all documented in Google, Roth Ladoad.
Hurt feelings are a fucking bitch when you have thin skin, eh Roth?
LOL
RS
>RS schrieb:
>> I haven't had a chance to play through either KittyHawk or Burman.
>> I've heard some good things though. Particularly curious about the
>> Burman. Partridge transformers, right?
>>
>
>right, it has Partridges.
>I must confess, the burman was a "never heard one, should have one,
>can't try one, so buy one" ebay purchase. I'm not so much convinced
>about the tone. It's "very special" and has a unique sound and handling
>of the controls. I have not invested much time to try it out; it just
>sits there.
Do you happen to have a schematic?
>> Hope it went well, Jochen. Always nice to hear what the toys can do
>> when they're cranked up. Sounds like the 5E3 is still your favorite.
>
>It's always essential to chose the right tool for the particular job.
>The 5E3 is a no brainer for this kind of jam session. Club with 80-100
>guests. Loud enough to cut through, not earshattering. No miking of the
>amps or the drum kit at all, just the vocs and sometimes a baritone sax.
>Set it and forget it. It has worked perfectly for years now and all the
>players who use the amps are happy.
Ah, so it was a gig. I thought you were talking about a jam.
Baritone sax is unusual. Don't see that often except in bigger
sections. What tunes do you use the bari player on?
>What's better than one 5E3 on a stage? Two 5E3s ;-))
Yeah, for louder drummers, just keep hauling more 5E3's up on stage.
<g> I like that style of amp in that it sings at normal 'drummer'
levels. Good for blues. For rhythm or clean sounds, Vibroluxes and
Pros are nice. They'll still sing when you get 'em cranked a bit.
>> BTW, have you had a chance to compare the Red Fang to your Vox Blue?
>No hav not manageed it yet - i had an old completely butchered "brown
>super" restauration on the bench for months. It haunted me with a weird
>hum on the vibrato channel.
>
>Fortunately i found the reason on Sunday night this week - The Volume
>pot was wired backwards from the factory !
That's an odd one. So the hum increased as the volume was turned
down.
>Now there's a 400PS waiting and unfortunately a lot of work on my day
>time job. Too many projects, too little time on my hands....
Let me know when you get a chance to try the Red Fang. Seems like
we're after the same kinds of sounds, so your opinion will help.
Ordinarily I'd just buy one, but I've accumulated way too many
orphaned speakers too. Trying to curb bad habits.
jh
> On Sat, 07 Mar 2009 14:09:13 +0100, jh <j...@org.de> wrote:
>
>> RS schrieb:
>
>>> I haven't had a chance to play through either KittyHawk or Burman.
>>> I've heard some good things though. Particularly curious about the
>>> Burman. Partridge transformers, right?
>>>
>> right, it has Partridges.
>> I must confess, the burman was a "never heard one, should have one,
>> can't try one, so buy one" ebay purchase. I'm not so much convinced
>> about the tone. It's "very special" and has a unique sound and handling
>> of the controls. I have not invested much time to try it out; it just
>> sits there.
>
> Do you happen to have a schematic?
I think i have it somewhere. I will look for it.
>
>>> Hope it went well, Jochen. Always nice to hear what the toys can do
>>> when they're cranked up. Sounds like the 5E3 is still your favorite.
>> It's always essential to chose the right tool for the particular job.
>> The 5E3 is a no brainer for this kind of jam session. Club with 80-100
>> guests. Loud enough to cut through, not earshattering. No miking of the
>> amps or the drum kit at all, just the vocs and sometimes a baritone sax.
>> Set it and forget it. It has worked perfectly for years now and all the
>> players who use the amps are happy.
>
> Ah, so it was a gig. I thought you were talking about a jam.
Oh no it - is - a jam, just a regular one. Just think about a rhearsal
of a band with 250 members and only 40 show up ;-)
>
> Baritone sax is unusual. Don't see that often except in bigger
> sections. What tunes do you use the bari player on?
>
Nothing particular, the guy is great, he joins whenever he likes...
We always have 2-5 sax players.
>> What's better than one 5E3 on a stage? Two 5E3s ;-))
>
> Yeah, for louder drummers, just keep hauling more 5E3's up on stage.
> <g> I like that style of amp in that it sings at normal 'drummer'
> levels. Good for blues. For rhythm or clean sounds, Vibroluxes and
> Pros are nice. They'll still sing when you get 'em cranked a bit.
Don't laugh, but my vibrolux is not that louder than the 5E3 - just
different. The sweet spot of the VR is "mildly raunchy leads" with
perfect fonky rhythm sounds when the guit vol is turned a tad down.
I bet the loudness thing is really in the speakers. Wit 35W the vibro
should really be a lot louder than the deluxe, but it simply ain't.
It's definately a matter of efficiency. The screaming sound of the 5E3
is gorgeous and th "clean" although not really clean ain't bad.
I just replaced the old CTS alnicos with some jensen RI P10Rs, but it
might happen that the CTSes go back in there.
At the jam, my vicky has convinced the other organizer to buy one for
himself, so we have one on every side of the stage. My old JMP 2203
serves as a "bass amp" - not bad either.
>
>>> BTW, have you had a chance to compare the Red Fang to your Vox Blue?
>
>> No hav not manageed it yet - i had an old completely butchered "brown
>> super" restauration on the bench for months. It haunted me with a weird
>> hum on the vibrato channel.
>>
>> Fortunately i found the reason on Sunday night this week - The Volume
>> pot was wired backwards from the factory !
>
> That's an odd one. So the hum increased as the volume was turned
> down.
YEP exactly. I just did not see it, until i made thorough resistance
comparisons with the normal channel. This is the third factory induced
bug i have found in a pre 70ties Fender. I searched everywhere, but just
overlooked it. It was driving me nuts.
>
>> Now there's a 400PS waiting and unfortunately a lot of work on my day
>> time job. Too many projects, too little time on my hands....
>
> Let me know when you get a chance to try the Red Fang. Seems like
> we're after the same kinds of sounds, so your opinion will help.
> Ordinarily I'd just buy one, but I've accumulated way too many
> orphaned speakers too. Trying to curb bad habits.
I'll do so..
regards
Jochen