[matthew j henschel]

Anyone have any pictures of the board and/or the filter cap layout for this
beast? It would help immensely! Thanks...

[Phil Allison]

"matthew j henschel"

Anyone have any pictures of the board and/or the filter cap layout for
this
beast? It would help immensely! Thanks...



** Like most older Fenders, the filter caps have their own mounting card (
using hollow studs) mounted under the chassis.

The ( all pigtail) caps are arranged basically in the same order as in the
schematic, with the two 220uF main filter caps first with the 100kohms bleed
resistors mounted along side each one.

The 1kohms and 4.7 kohms series dropping resistors are on this card too.




....... Phil

[matthew j henschel]

"Phil Allison" wrote in
:


"matthew j henschel"

Anyone have any pictures of the board and/or the filter cap layout
for this
beast? It would help immensely! Thanks...



** Like most older Fenders, the filter caps have their own mounting
card ( using hollow studs) mounted under the chassis.

The ( all pigtail) caps are arranged basically in the same order as in
the schematic, with the two 220uF main filter caps first with the
100kohms bleed resistors mounted along side each one.

The 1kohms and 4.7 kohms series dropping resistors are on this card
too.




...... Phil





What's in there now is two 220uf, followed by three 20uFs, followed by
two 100's. I'm having trouble locating the 20's on the schematic...

[matthew j henschel]

François Yves Le Gal wrote in
:

On Tue, 13 Mar 2007 22:56:49 GMT, matthew j henschel
wrote:

What's in there now is two 220uf, followed by three 20uFs, followed by
two 100's. I'm having trouble locating the 20's on the schematic..

http://www.ampwares.com/ffg/schem/tw..._135_schem.jpg

Look above V5, you'll find two 20æ. The other one is right after the 100K
bleeders in the B+ supply.

Ah-hah, I see the other two now, thanks. What do they do? I'm pretty
green with all this stuff.

I'm having some farting and distortion that I think may be a partially
blown OPT, but haven't nailed it down yet...

While I've got the ear of a guru--- I'm also noticing the reverb and vibe
works on both channels, and you can hear the tank output if the volume on
both channels is all the way down but the verb is up. I can't see anything
that in particular looks like a mod and it all -appears- to match the
schematic. Any suggestions as to a starting point?

Thanks!

-Matt

[Phil Allison]

"matthew j henschel"

While I've got the ear of a guru--- I'm also noticing the reverb and vibe
works on both channels, and you can hear the tank output if the volume on
both channels is all the way down but the verb is up.


** How silly.

If the reverb volume is up - you will hear twangs if it is bumped.

Channel vols have nothing to do with that.

But only the vibrato channel will drive the tank.



...... Phil

[matthew j henschel]

"Phil Allison" wrote in
:


"matthew j henschel"

While I've got the ear of a guru--- I'm also noticing the reverb and
vibe works on both channels, and you can hear the tank output if the
volume on both channels is all the way down but the verb is up.


** How silly.

If the reverb volume is up - you will hear twangs if it is bumped.

Channel vols have nothing to do with that.

But only the vibrato channel will drive the tank.



..... Phil




Fair enough. Any suggestions on hunting down the channel coupling then?
Definitely getting 'verb and trem from the normal channel.

[Phil Allison]

"matthew j henschel"

While I've got the ear of a guru--- I'm also noticing the reverb and
vibe works on both channels, and you can hear the tank output if the
volume on both channels is all the way down but the verb is up.


** How silly.

If the reverb volume is up - you will hear twangs if it is bumped.

Channel vols have nothing to do with that.

But only the vibrato channel will drive the tank.



Fair enough. Any suggestions on hunting down the channel coupling then?
Definitely getting 'verb and trem from the normal channel.



** Visual inspection is all you can do.

As you could not even find the electros on a schem - this is a skill you
need to learn.



....... Phil

[matthew j henschel]

"Phil Allison" wrote in
:


Fair enough. Any suggestions on hunting down the channel coupling
then? Definitely getting 'verb and trem from the normal channel.



** Visual inspection is all you can do.

As you could not even find the electros on a schem - this is a
skill you
need to learn.



...... Phil



I couldn't find those two 20's for the life of me :-) The rest of em where
no trouble.

I've been focusing around the two 100k resistors where the two channels
mix, but am not having much luck. I removed the board and scrubbed it
down, which helped none. I'm thinking it's a circuit modification
somewhere, but my amp theory is pretty light.

I've got a scope and a signal generator and the drive to explore... any
suggested reading or places to start?

[Phil Allison]

"matthew j henschel"


I've been focusing around the two 100k resistors where the two channels
mix, but am not having much luck. I removed the board and scrubbed it
down, which helped none. I'm thinking it's a circuit modification
somewhere, but my amp theory is pretty light.


** V1B and V2B share a common ( 820 ohm) cathode resistor.

The 25uF bypass cap may be faulty - try a new one.




........ Phil

[matthew j henschel]

"Phil Allison" wrote in news:55p9kbF253pu2U1
@mid.individual.net:


** V1B and V2B share a common ( 820 ohm) cathode resistor.

The 25uF bypass cap may be faulty - try a new one.



Nice! Spot on. Thanks Phil, you nailed it. Guess it might be time to
change all of em. Hopefully the high freq distortion and bass muddiness is
in the output stage caps, but I'm not holding my breath. The opt sure
looks like it got hot.

Thanks again.

[Phil Allison]

"matthew j henschel"
"Phil Allison"


** V1B and V2B share a common ( 820 ohm) cathode resistor.

The 25uF bypass cap may be faulty - try a new one.


Nice! Spot on. Thanks Phil, you nailed it. Guess it might be time to
change all of em. Hopefully the high freq distortion and bass muddiness
is
in the output stage caps, but I'm not holding my breath. The opt sure
looks like it got hot.

Thanks again.



** Long distance diagnosis sans telescope is all luck really.




......... Phil

[J.P.]

On Wed, 14 Mar 2007 03:42:11 GMT, matthew j henschel
wrote:

"Phil Allison" wrote in
:


Fair enough. Any suggestions on hunting down the channel coupling
then? Definitely getting 'verb and trem from the normal channel.



** Visual inspection is all you can do.

As you could not even find the electros on a schem - this is a
skill you
need to learn.



...... Phil



I couldn't find those two 20's for the life of me :-) The rest of em where
no trouble.

I've been focusing around the two 100k resistors where the two channels
mix, but am not having much luck. I removed the board and scrubbed it
down, which helped none. I'm thinking it's a circuit modification
somewhere, but my amp theory is pretty light.

I've got a scope and a signal generator and the drive to explore... any
suggested reading or places to start?
Electric Guitar Amplifier Handbook by Jack Darr ...AES ... J.P.

[matthew j henschel]

François Yves Le Gal wrote in
:

On Wed, 14 Mar 2007 17:54:43 GMT, J.P. wrote:

Electric Guitar Amplifier Handbook by Jack Darr ...AES ...

Agreed. This book is a classic and a must-read for any aspiring amp
jock

The more interesting chapters, "Service procedures and techniques",
have been scanned (quality is OK - not great) and are freely
downloadable as PDF files.

http://www.pacificrecone.com/JackDarrBook.html
http://www.diyguitarist.com/Misc/J_Darr.htm

BTW, the reprint is published by OCSL.

http://www.audioxpress.com/bksprods/products/bkaa69.htm



This is exactly what I was looking for. Thanks a million guys!

-Matt

[Phil Allison]

"matthew j henschel"


http://www.audioxpress.com/bksprods/products/bkaa69.htm

This is exactly what I was looking for. Thanks a million guys!


** Not really.

Despite the overoptimistic jacket blurb - that book was written in 1965
( ie in the tube era) by a professional radio and TV repair man for the
benefit of OTHER professional radio and TV repair men.

The author assumes the reader is familiar with consumer level tube
technology and has a well equipped workshop.

It ain't for novices.



...... Phil

[matthew j henschel]

"Phil Allison" wrote in
:


"matthew j henschel"


http://www.audioxpress.com/bksprods/products/bkaa69.htm

This is exactly what I was looking for. Thanks a million guys!


** Not really.

Despite the overoptimistic jacket blurb - that book was written in
1965
( ie in the tube era) by a professional radio and TV repair man for
the benefit of OTHER professional radio and TV repair men.

The author assumes the reader is familiar with consumer level tube
technology and has a well equipped workshop.

It ain't for novices.



..... Phil



I'm definitely not a professional and very clearly in the novice range,
but have a basic understanding and a basic workshop... gotta start
somewhere, and this looks to be as good as any place. Any
recommendations of your own, Mr Allison?

-Matt

[Phil Allison]

"matthew j henschel"

http://www.audioxpress.com/bksprods/products/bkaa69.htm

This is exactly what I was looking for. Thanks a million guys!


** Not really.

Despite the overoptimistic jacket blurb - that book was written in
1965
( ie in the tube era) by a professional radio and TV repair man for
the benefit of OTHER professional radio and TV repair men.

The author assumes the reader is familiar with consumer level tube
technology and has a well equipped workshop.

It ain't for novices.



I'm definitely not a professional and very clearly in the novice range,
but have a basic understanding and a basic workshop... gotta start
somewhere, and this looks to be as good as any place.


** Well - you don't need any advice from anyone.


Any recommendations of your own, Mr Allison?


** Consider ****ing off .





........ Phil

[matthew j henschel]

I'm definitely not a professional and very clearly in the novice range,
but have a basic understanding and a basic workshop... gotta start
somewhere, and this looks to be as good as any place.


** Well - you don't need any advice from anyone.


Any recommendations of your own, Mr Allison?


** Consider ****ing off .





....... Phil



Hey no disrespect intended. I need advice from everyone in fact, that's
why I asked.

I'll **** off now.

-Matt

[J.P.]

On Fri, 16 Mar 2007 04:26:12 GMT, matthew j henschel
wrote:

François Yves Le Gal wrote in
:

On Wed, 14 Mar 2007 17:54:43 GMT, J.P. wrote:

Electric Guitar Amplifier Handbook by Jack Darr ...AES ...

Agreed. This book is a classic and a must-read for any aspiring amp
jock

The more interesting chapters, "Service procedures and techniques",
have been scanned (quality is OK - not great) and are freely
downloadable as PDF files.

http://www.pacificrecone.com/JackDarrBook.html
http://www.diyguitarist.com/Misc/J_Darr.htm

BTW, the reprint is published by OCSL.

http://www.audioxpress.com/bksprods/products/bkaa69.htm



This is exactly what I was looking for. Thanks a million guys!

-Matt
Check here also. Several good references. Please look past the
resident trolls. Their undies get in a knot if someone new comes
along.Too many rejections from chicks I suppose...J.P.