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Topic: Webb restoration |
Brad Sarno
From:
St. Louis, MO USA
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Posted 16 Dec 2003 2:52 pm |
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Well it was hardly a restoration as the amp worked quite well. It's a '78 SN#960, a burgundy/red one with a JBL E130-4. I went in there and replaced every single electrolytic cap. (Except on the graphic EQ board which I haven't been using) A couple dozen in all. While in there I noticed a few places where there were either electrolytics or ceramic caps that were in the signal path or the tone circuits. Often times an engineer will choose ceramic caps in places that are better served by using film caps, ususally for cost and space reasons. To an engineer a ceramic cap may fit the design based on it's value, but in my experience, ceramic caps are best used for RF filtering, not signal path or tone circuits. They tend to be comparitively harsh or grainy sounding, not smooth. So just like in a Twin or a Session, I replaced all the electrolytics and "crapacitors" with nice film types and new fresh electrolytics where appropriate. There were a few in the reverb circuit and a few more in the tone circuit. No values were changed, only quality upgraded. Where there were 1uF electrolytics in the signal path, I used a film cap instead. Basic audiophile or boutiquie amp approach to cleaning up the sound.
The result is truly amazing. Even my band members commented on it. And I thought the amp sounded GREAT before the cleanup. It's quieter, cleaner, more 3-Dimensional, warmer, more lush, sweeter, more open, blah blah blah. The reverb circuit sounds better too. If anyone has an old Webb, they may want to consider more than just the power supply cap replacement.
Always tweakin,
Brad Sarno
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Chris Erbacher
From:
Sausalito, California, USA
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Posted 16 Dec 2003 4:09 pm
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| thanks brad, i am always tweaking too and i'm wondering how much it costs in supplies to do all this? thanks for your posts |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 16 Dec 2003 4:41 pm
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The big power supply caps were about $10 each. All the rest of them were about $20 total. So for about $30 to $40 you can do this. I found most everything I needed thru Mouser. Once I figured out how simple their parts search engine works, I prefer it to Digi-Key. If you want a parts list I can try and put it together.
Brad |
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Larry Behm
From:
Mt Angel, Or 97362
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Posted 16 Dec 2003 5:36 pm
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Brad posting the list sounds good to me also.
Larry Behm |
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Jerry Roller
From:
Van Buren, Arkansas USA
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Posted 16 Dec 2003 8:30 pm
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Brad, I too, would like this information.
Thanks, Jerry |
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Kevin Hatton
From:
Buffalo, N.Y.
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Posted 16 Dec 2003 9:08 pm
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| Brad, bravo, bravo! Please post the parts list for the rest of us. Great work. |
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Chris Erbacher
From:
Sausalito, California, USA
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Posted 16 Dec 2003 11:01 pm
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i'd be really happy to have a list of your changes. the last few days have been great days for me in finding out information about stuff i haven't been able to get my hands on thanks to you and kevin. and my six string friends wonder why i spend so much time at this site. thanks again guys  |
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Rick Johnson
From:
Wheelwright, Ky USA
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Posted 17 Dec 2003 4:50 am
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Its very rewarding to learn how
to service your amps. Just one word
of caution. There is enough charge
in most amps to knock you out or kill
you. Please learn how to discharge
the caps before attempting any work
inside the chassis.
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Rick Johnson
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Brad Sarno
From:
St. Louis, MO USA
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Posted 17 Dec 2003 5:58 am
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Amen Rick!!! Especially in those tube amps.
Brad |
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Michael Haselman
From:
St. Paul
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Posted 17 Dec 2003 7:40 am
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Brad, I've got number 969, so ours are very close in age. That list would be very nice to have, even though I had mine gone over 4 years ago and is working very nicely.
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Marrs D-10, Webb 6-14E |
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Bill Cutright
From:
Akron, OH
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Posted 17 Dec 2003 9:09 am
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| Made me look... it's either 686 or 989. (it's a fairly early one. I'd really have to do some dustin' to nail when I bought it-new.) Thing that really peavy'd me about this thing was the pots became scratchy as hell after a relatively short time. Maybe he upgraded in later versions(?) |
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Ken Fox
From:
Nashville GA USA
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Posted 17 Dec 2003 10:57 am
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| Scratchy pots can often be due to DC leakage on the tone caps. About .5 volts of leakage will make pots extremely scratchy! |
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Steve Stallings
From:
Houston/Cypress, Texas
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Posted 17 Dec 2003 4:35 pm
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quote:
There is enough charge
in most amps to knock you out or kill
you.
Yeah budddy... you know that little blue boxxy looking thing inside the Mesa Boogie Studio Pre? Don't touch it and the chassis at the same time when you are changing out your tubes. Rang my bell....
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God Bless,
Steve Stallings
www.pedalsteeler.com
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Larry Behm
From:
Mt Angel, Or 97362
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Posted 20 Dec 2003 8:29 am
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So Brad when does the list of componets appear here?
Larry Behm |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 20 Dec 2003 10:00 am
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Larry, I've got a partial list right now but I want to get it all together so it's complete and done. I want it to be a simple one-time order from Mouser so there's no messin around. Hopefully by the New Year.
Brad
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Jimmie Webb
From:
Antioch, California, USA
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Posted 27 Dec 2003 4:21 pm
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In the last few days I have been reading several Replies to a few different topics such as:
Have you hugged your Webb today?
WTB/Webb 614 amp
Webb restoration
I hope all of you Authors and Repliers had a good Christmas and bring in a Happy New Year. I would like to reply to all of you individually but there is not enough time.
I do appreciate what all of you are doing for me and the Webb Amplifier.
Thanks Again,
Jimmie D. Webb
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Brad Sarno
From:
St. Louis, MO USA
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Posted 27 Dec 2003 4:24 pm
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Hey Jimmie, we appreciate what you've done for us with your Webb Amplifier!
Merry Christmas and Happy New Year!
Brad Sarno
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Kevin Hatton
From:
Buffalo, N.Y.
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Posted 27 Dec 2003 8:50 pm
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| Best steel amp out there Mr. Webb. |
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Bill Plemmons
From:
Simpsonville, SC
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Posted 1 Jan 2004 5:05 pm
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| Brad, I have #778 and have been thing about doing a cap job. Your list would be a godsend. The amp sounds good but I think it may be getting tired. Bought it in 1978. The best amp I've ever owned. |
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Gino Iorfida
From:
Pittsburgh, Pennsylvania, USA
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Posted 1 Jan 2004 5:59 pm
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Brad,
Please don't take this as a cut to your abilities, which this is not intended to be, however, I have to disagree on the "use of creamic caps in places better served by film caps" statement.
Granted, YES, they can be cheaper, however, DEPENDING on the amplifier in question etc, SOMETIMES a ceramic cap WOULD be preferred for tone over a film or mica cap. This is highly subjective etc. For example, I know a LOT of guys who believe that in Fender amps, that replacing all the ceramic caps with mica's is the only way to go, while others will find mica's to be to brittle and sterile sounding, and the ceramics 'warmer' sounding.
Where the differentiation goes, the studio engineer/hifi type mindset folks will prefer the mica's and film caps, where the low-fi/retro-tech types will be jumping up and down for the ceramics and film caps.
I guess the point I'm making is NOT to say your way of thinking is wrong, but to give another opinion -- it would be cool if one could have 2 amps set up (all with updated electro caps etc), and allow one to hear the difference between ceramic or film or mica caps in various places to decide for themselves (as some like stainless steel and others like nickel wound strings etc).
again, no malice intended, rather another point of view to consider  |
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Bobby Lee
From:
Cloverdale, California, USA
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Posted 1 Jan 2004 8:55 pm
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Mine is serial #875, bought new in 1978. I'd like to do this restoration too. Thanks for the suggestion, Brad.
------------------
 Bobby Lee - email: quasar@b0b.com - gigs - CDs, Open Hearts
Sierra Session 12 (E9), Williams 400X (Emaj9, D6), Sierra Olympic 12 (C6add9),
Sierra Laptop 8 (E6add9), Fender Stringmaster (E13, A6),
Roland Handsonic, Line 6 Variax |
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Kevin Mincke
From:
Farmington, MN (Twin Cities-South Metro) USA
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Posted 2 Jan 2004 4:09 pm
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#749 from 1977 may also benefit from this overhaul! Gino makes a valid point however when using ceramic vs film/mica caps. It would be intersting to listen to them A/B'd with & without the changes. 
Maybe Mr. Webb will comment on Brad's upgrades/replacements to his amps.
I'll be looking for the marked schematic.
Thanks Brad!! |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 2 Jan 2004 7:15 pm
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Gino, I agree, it's all taste in tone coloration. With an audiophile mentality, it's natural to be lead to film caps, they're cleaner, higher performance, have less coloration. On guitar amps that can often sterilize the tone. I've heard it on some Fender re-cap jobs. My Healy-fied Twin for example sounds pretty cold and sterile with a Strat or Tele now, but steel seems to benefit for the added fidelity. I've found that for regular guitar the graininess of ceramic caps does a nice harmonic thing when the tubes get driving. In the Webb, and the Session 400, the good film caps seem to let more subtlety and nuance come thru. To my ear, these clean solid state power amps take on a smooth, velvety, sweet quality, more lush and 3D, warmer. It's definitely A sound, not necessarily THE sound. It's an experiment for anyone wanting to hear it. It's easy enough to go back if the film caps take away from the sound. To my ear, the film caps open up the amp's potential and let the warmth of the guitar come thru real nice.
I think that in many amps when an electrolytic cap is used in a coupling stage, that's almost always going to be based on a cost issue because when the values get high enough, film caps get too large and expensive. Electrolytics are the compromise in that situation. Some people prefer tantalum instead, or real big film caps if they can be fit and afforded. But in guitar amp tone shaping circuits, I agree that mica and ceramic have often been chosen for their particular tonal quality. To my ear, I think the right film caps in a solid state steel amp can actually be the warmest of all the possibilities. It is a hi-fi approach and by that I mean that it makes the amp cleaner and more out-of-the-way of the guitar's signal. When I play 6-string guitar thru my '68 Deluxe, that whole mentality is reversed. The amp's dirt and coloration becomes the majority of the sound in that case.
Brad Sarno
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Dave Grothusen
From:
Scott City, Ks
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Posted 3 Jan 2004 6:15 am
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Brad sounds like you really have a handle on the Webb amp. Do you know where a person might start looking for an intermitant problem. Occasionally the thing will go to "Fuzz tone" mode. You can't play through it with any drive at all at that point. Once turned off and not used for awhile it may not do it again for quite sometime.
Thanks for any ideas. |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 3 Jan 2004 8:16 am
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Dave, I've only had familiarity with the Webb for the last few months. I haven't dealt with that particular problem, yet. First thing I'd do would be open her up, follow the signal path from the input and look for any loose or poorly soldered components. Maybe try some freeze spray to check solder joints or funny parts. I bet Ken Fox, Gino Iorfida, or Woody Woodell could help you better approach that issue.
Brad |
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