Polytone reverb problems
ScotGormley
Anyone know the primary cause and if there's a cheap fix? I found a
used MiniBrute IV that was supposed to be fully functional, but the
reverb was dead when the amp arrived. I took it apart, but could find
no obvious issues (no loose cords or disconnected RCA connectors).
I do love the warm sound of those old 3-knob units (volume, bass &
treble), though. (But it's a dry warmth, without any reverb ;-))
Kevin Van Sant
<scot.g...@yahoo.com> wrote in message
<2bb00453-92d7-4bcf...@37g2000prx.googlegroups.com> :
those spring reverb tanks that are used in almost all amps (non
digital of course) come from the same manufacturer.
http://www.accutronicsreverb.com/
The problem is almost certainly in the tank and not in the polytone.
There are some very this wire leads in those things that are
vulnerable to failing. But the tanks are easily replaced and just
cost about $30. I've had to change the reverb in my Evans and
Polytone. Just pull the old one first so you can get the numbers off
it in order to get the right replacement.
________________________________________
Kevin Van Sant
http://www.kevinvansant.com
info, music, videos, etc...
Lord Valve
They're easy to fix, depending on where the break is..
Inside the tank, there will be a set of two leads
associated with each RCA connector. Gently
stress them (one at a time) with a chopstick
to see if they are broken. If they're broken off
at the RCA (most common failure) then you
can just strip a little of the insulation off and
solder them back on...don't worry about sticking
them through the holes in the terminals, just tack
solder them to the face of the terminal. If they're
broken off at the transducer end, it's trickier - if
you have a stub sticking out of the transducer,
you can pull the insulation off, strip the end
of the wire coming from the RCA, and then
tack-solder the pieces together. Once you've
done this, make sure the bare part isn't touching
anything made of metal and then encase the
area in a glob of clear silicone caulk. (Stick the
repaired connection to the transducer bobbin,
which is plastic.) If a stub isn't present, the
fix - good aboout half the time - is to dig into
the bobbin with an Exacto knife to find enough
wire to solder to. (Not recommended - in order
for this to work, you'd have to be me. And you
ain't. ;-)
Lord Valve
Expert (please obsess)
ScotGormley
> Kevin Van Sant wrote:
> > On Mon, 6 Dec 2010 15:40:34 -0800 (PST), ScotGormley
> > <2bb00453-92d7-4bcf-8da6-643300a4c...@37g2000prx.googlegroups.com> :
>
> - Show quoted text -
Thanks, guys. I had an Evans I bought new from the company, and it
(the reverb) arrived DOA, too. Evans sent me a new tank that I used to
replace the defective one. Really griped me to have to do this on a
new, $1300 amp. If I can work up the nerve, I may try Lord Valve's
suggestions.
Dan Adler
I took it to a tech in NYC who replaced it in less than a minute while
I was waiting... about $100. No problems since.
Guy
I have an old early 80's Mini Brute III which is similar to the IV
except for lacking reverb.
These days I only use it if I need a bit of extra air moving
capability and that was when I found that driving the Polytone from
the line output of an AER Compact 60 was an unexpected success. The
AER has a very clean amplifier with quite a nice built-in digital
reverb. It made a big improvement to the MB III's already good sound.
So possibly an alternative to repairing these old reverb units might
be to use a separate digital preamp. Especially if one doesn't like
having to open the box up and get out the soldering iron.
Guy
Kevin Van Sant
wrote in message
<ead9899f-6117-49aa...@i25g2000prd.googlegroups.com> :
>
>I took it to a tech in NYC who replaced it in less than a minute while
>I was waiting... about $100. No problems since.
Wow, that's the business to be in! $70/minute!
Mark Cleary
"Kevin Van Sant" wrote in message
news:38dsf6pvme2n54kg6...@4ax.com...
On Tue, 7 Dec 2010 03:35:22 -0800 (PST), Dan Adler <d...@danadler.com>
wrote in message
<ead9899f-6117-49aa...@i25g2000prd.googlegroups.com> :
>
>I took it to a tech in NYC who replaced it in less than a minute while
>I was waiting... about $100. No problems since.
Wow, that's the business to be in! $70/minute!
One reason I quit playing and started doing repairs. I can make much more
money repairing guitars than playing them. It could say something about my
playing but seriously, since I don't gig anymore and do repairs I really do
much much better cash flow.
Deacon Mark Cleary
Epiphany Church
Lord Valve
Damn - a C-note for installing a $20 part in less than a minute?
That's it - I'm movin' to New York...
ehelfrich
soon after I got it the reverb stopped working. Being the inquisitive
type I pulled the back off the amp to see if I could figure out what
was wrong. The reverb tank is attached to the back panel and it
became apparent pretty soon what the problem was. One of the wires
from tank had pulled loose from the printed circuit board when a prior
owner had been in a hurry to get into the amp. Why would anyone be in
a hurry to open up an amp? Looking a little further I noticed a
prior owner had been using the bottom of the amp to store about two
dozen syringes and some pharmaceuticals still in the shrink packs. A
quick trip to the neighbor's trash can and the potential legal problem
was out of the way and a careful bit of soldering and the reverb was
back again. Its too bad I had already left feedback on the ebay
purchase so I was unable to inform the seller about the junky amp he
sold me.
On Dec 6, 6:40 pm, ScotGormley <scot.gorm...@yahoo.com> wrote:
Phil
> On Mon, 6 Dec 2010 15:40:34 -0800 (PST), ScotGormley<scot.gorm...@yahoo.com> wrote in message
>
> <2bb00453-92d7-4bcf-8da6-643300a4c...@37g2000prx.googlegroups.com> :
>
> >So what's the deal with the reverb failures on so many old Polytones?
> >Anyone know the primary cause and if there's a cheap fix? I found a
> >used MiniBrute IV that was supposed to be fully functional, but the
> >reverb was dead when the amp arrived. I took it apart, but could find
> >no obvious issues (no loose cords or disconnected RCA connectors).
>
> >I do love the warm sound of those old 3-knob units (volume, bass &
> >treble), though. (But it's a dry warmth, without any reverb ;-))
>
> those spring reverb tanks that are used in almost all amps (non
>
> The problem is almost certainly in the tank and not in the polytone.
> There are some very this wire leads in those things that are
> vulnerable to failing. But the tanks are easily replaced and just
> cost about $30. I've had to change the reverb in my Evans and
> Polytone. Just pull the old one first so you can get the numbers off
> it in order to get the right replacement.
>
> ________________________________________
> Kevin Van Sant
>
> http://www.kevinvansant.com
> info, music, videos, etc...
Last year I ordered a new tank for my MegaBrute (by part number),
replaced it, and it (yes, the new tank) stopped working in less than
two weeks! I gave up -- now I just use a Boss RV-3 reverb. It always
works and sounds great.
Dan Adler
> On Tue, 7 Dec 2010 03:35:22 -0800 (PST), Dan Adler <d...@danadler.com>
> wrote in message
>
>
>
> >I took it to a tech in NYC who replaced it in less than a minute while
> >I was waiting... about $100. No problems since.
>
> Wow, that's the business to be in! $70/minute!
>
Kevin,
That includes the price of the spring replacement, of course.
Tim McNamara
recommended by Polytone; they opened it up and discovered the reverb had
never been connected in the first place...
--
Gotta make it somehow on the dreams you still believe.
Joe Giglio
that's because all polytone's have an anti-body that rejects &
ultimately destroys their own internal reverbs...
+ the worst quality control!
Great White Buffalo
These things are usually very easy to fix. Typically a resistor comes
loose form the PCB board. I've had 2 or 3 just like that.
The wa yi fixed mine was to turn off the amp, take the top (preamp?)
board out and hand test to see which components had come unsoldered.
Mine very never visually apprarent, but when you press on a component
or see one that looks like it may astick out a little mroe than others
and press on it, it becomes apparent.
therwise, those thingsd were built like trucks with good quality
components and cabinetry.
I'm referring to 70's and 80's m,doels, which are all I've ever owned.
Grerg/oasysco
Kevin Van Sant
wrote in message
<adfc738d-25ad-4f33...@h17g2000pre.googlegroups.com> :
>>
>> >I took it to a tech in NYC who replaced it in less than a minute while
>> >I was waiting... about $100. No problems since.
>>
>> Wow, that's the business to be in! $70/minute!
>>
>
>Kevin,
>
>That includes the price of the spring replacement, of course.
right, that's why I didn't say $100/min :)