• Guys, we've spent considerable money converting the Les Paul Forum to this new XenForo platform, and we have ongoing monthly operating expenses. THE "DONATIONS" TAB IS NOW WORKING, AND WE WOULD APPRECIATE ANY DONATIONS YOU CAN MAKE TO KEEP THE LES PAUL FORUM GOING! Thank you!

Which caps to replace Astrons in tweed amps?

bluesroom

Member
Joined
Jul 17, 2001
Messages
394
The question at hand is— to replace or not to replace ? Lol
.....and if to replace —-what to replace with?!!!
If you buy vintage tweeds and want to play it them, this is a constant dilemma. I still don’t know a good solution. I do know that caps go bad. The last thing I want to do is blow up an output transformer in a deluxe. I want amps to sound their best ofcourse — but I also want them to retain their vintage value. If caps are replaced, I want the guts to look like the work of art they once were, not just a bunch of orange generic caps.
I know some guys replace the the vintage cardboard over new caps. I’m not sure how I feel about this. I do know that If I asked an amp tech to do this, they’d tell me to invest in medication instead, lol.......
Ok.I get it. I understand the techs position. They fix and service amps to work and sound good. They certainly don’t want call backs because they left borderline parts in an amp to look vintage for the nut that owns them.
At the current time I save the original parts to sell with an amp if they ever get sold. If it’s a cap here or there, it doesn’t bother me as much. But those old tweeds are full of those yellow astrons. If they are all replaced there’s not much left. It ends up looking either like a modern amp or a vintage one that someone just replaced every component on. I’d like it to look like someone respected what these amps once were. Any of you guys have a solution to the playability vs collectibility Problem? And when the Yellow astrons are replaced, or other caps, what a good replacement both in function and look?
thanks
 
Last edited:

Don

Well-known member
Joined
Dec 1, 2001
Messages
5,688
Replace the electrolytics for sure. F&T are good. Yellow Astron coupling caps get leaky. Keep them in the amp if possible and replace them as required. Possibly consider replacing them between the phase inverter and power tubes to prevent issues. I like to replace B+ dropping resistors as well.
 

LeonC

Active member
Joined
Aug 30, 2002
Messages
380
You'll probably get as many opinions/approaches as you get replies. We all have our own priorities. I'm much more of a player than a collector. I'll typically concentrate on getting the amp sounding its best. I always save the parts I've replaced in a baggie and label them. So if the day comes that I want to sell the amp, I tell the prospective buyers that I have and will provide all the original parts. I'll mention this and provide photos in my for-sale ads/auction. If you're more of a collector...well then, you're probably better off leaving it pretty much alone. What I've often done is look for beaters, amps that have already been mucked with, buy them at a reasonable (lower) price and take them back to stock using decent quality parts. (I've been happy with Mallory 150 caps in Fenders. I've also been okay with Sozo blue caps in the not too distant past.

That said, another good approach is to stick to buying only amps that you get to inspect and play first and wind up being in pretty good shape w/o a lot of parts needing replacement.. Of course, they are rarer and rarer as each year passes...so it helps to live in a big metropolitan area and you have to be really, really patient. But I do occasionally run across an old amp that needs very little service. Typically...these are amps that run at lower voltages, e.g., some Valco-made amps. I recently worked on a Supro 1688TN that a buddy found here in LA. It was 100% original and just needed a couple crappy signal caps and the filter caps replaced, but most we were able to leave in there, to my surprise. The amp sounded good to start with but absolutely incredible afterwards.

Fenders tend to run at higher voltages and will often have seen more use and are typically in worse shape. For this reason... and ironically, they're more desirable and worth more. But I'll just avoid them myself. I'd prefer to buy a really well made, authentic clone.
 
  • Like
Reactions: Don

Hot_Snake

Member
Joined
Sep 26, 2010
Messages
193
Jupiter yellows are great for replacing old yellows Astron - same goes for the reds.
F&T or Sprague for electrolytics.
 

Wally

Well-known member
Joined
Feb 27, 2003
Messages
3,293
I don’t mind proper replacement of tone and coupling caps. The Older tweeds have paper in oil caps in those positions. Those need to be replaced IF you want to hear what the amp should sound like Just as all of the electrolytics should be replaced. If the resistors have drifted, they need to be replaced as well. A good tech knows when these components are not performing their sssigned task And why they need to be replaced.
yellow .Astrons used in the last half of that tweed era are more durable and stand the test of time better than do the PIO caps. However, when they need to be replaced they have to go. I have no problem using orange drops...lI have heard the results and they work...as long as the values are correct.
 

corpse

Well-known member
Joined
Jun 9, 2007
Messages
4,086
I had an extensive conversation on the topic of tone/electrical value of caps in guitars. Big Al set up a test bed that allowed measuring and then listening to caps in a circuit- this was done on the tone chain in a guitar mind you. His take away was as long as the value was correct the device sounded like the device.
He had collected tons of caps and spent serious time putting it together. He has mentioned this here before BTW- I am just regurgitating the story. Appearance is another thing. That makes no difference to my ears- and I resent having to reinstall the chassis in a Fender so I leave them alone until they sound off- I like looking at them, but internal appearance is just not a factor in amps for me.
Marshall cabs are an entirely different thing though.
 

TM1

Well-known member
Joined
Jun 27, 2003
Messages
8,032
Look & listen with your ears! Sozo makes a great Blue Molded clone besides their "mustard"(Iskra/Phillips) clones! Wima makes a Polyester cap that sounds wonderful in Fender's!
 

Señor Verde

Member
Joined
Jan 13, 2005
Messages
514
I tried Blue Sozos many years ago when they first came out. After burning them in for about 100 hours they sounded dull and not very clear.

My Tweed Deluxe clone came with Orange Drop 715 caps and it was harsh. I did some research and several people liked Orange Drop 6PS caps best for Tweed amps. I have the 6PS in my Tweed clone and Allen Blackface style amps and think they sound great! They don't look period correct, but who's going to see them when the amp is working?
 

Wallace

Member
Joined
Feb 23, 2003
Messages
874
I have blue Sozos in my 5E3 & 5F1 clones and they sound killer.
 

el84ster

Active member
Joined
Sep 10, 2001
Messages
1,376
I really like the blue sozo’s

man after 20 years of working on amps I now lean more toward replacing coupling caps, if they have any leakage at all, the amp will not sound its best. Any leakage to the grid of the next stage throws that bias off and typically you get sort of a slightly fuzzy unfocused sound.
If you want to hear the amp like it left the factory, replace everything that leaks even if it ‘still works’.
 
Last edited:

ampdan

Member
Joined
Feb 6, 2007
Messages
427
More Astrons.....?
 

Attachments

  • m950kn.jpg
    m950kn.jpg
    72.8 KB · Views: 7
  • IMG_1644.JPG
    IMG_1644.JPG
    196.9 KB · Views: 7
Top