Caps...Why am I driving myself nuts!!!

Express, Liverpool, Rocket, Dirty Little Monster, etc.

Moderators: pompeiisneaks, Colossal

Post Reply
jferris5
Posts: 27
Joined: Thu May 15, 2008 2:05 pm

Caps...Why am I driving myself nuts!!!

Post by jferris5 »

Hello, long time lurker first time poster here. After building a few Marshall and Fender style amps I'm ready to venture into the TW world. My next build will be an express.

I'm planning everything out now and with the PVC caps being hard to find I'm having trouble deciding what caps I want to use.

I usually lean toward the camp of no matter what brand/materiel a cap is .1uf is .1uf. I've used mallory, 715p's, Jupiter, sozo etc and I thought they all have performed well.

For what ever reason this build has me all caught up in what cap is going to sound the best in this express.

I'm leaning toward the Jupiter caps but it drives me nuts that they don't have a .022uf and my ADD doesn't want me to put in a few 1 off's.

I haven't tried the new sozo NextGen or blues yet.

I've read a few post that mention people don't care for the 715p's.

I know this topic has been beaten to death...lol I just wanted to see what other express builders are using these days and what your recommendations are.

Thanks!
James
RockinRocket
Posts: 628
Joined: Sun Nov 20, 2011 5:23 am

Re: Caps...Why am I driving myself nuts!!!

Post by RockinRocket »

No need to drive your self nuts over caps!
rooster has the Mallory PVC caps for sale in the for sale/ trade section of the forum!
User avatar
martin manning
Posts: 13080
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: Caps...Why am I driving myself nuts!!!

Post by martin manning »

Another good option is 600V polyester orange drops from AES, essentially equivalent to the Sprague 6PS.
Bob Simpson
Posts: 299
Joined: Fri Sep 07, 2007 5:43 pm
Location: Lakewood, CO

Re: Caps...Why am I driving myself nuts!!!

Post by Bob Simpson »

Welcome to the Dark Side, my young Jedi...

Folks here will help you through.

Best wishes.

Bob Simpson
Please understand that IMO an answer to this question is of no practical relevance at all. - Max
Bob S
Posts: 1575
Joined: Sat Feb 14, 2009 2:38 pm
Location: Up there with the Michiganders

Re: Caps...Why am I driving myself nuts!!!

Post by Bob S »

^^^ Hehehe!
Why Aye Man
User avatar
David Root
Posts: 3540
Joined: Fri Aug 04, 2006 3:00 pm
Location: Chilliwack BC

Re: Caps...Why am I driving myself nuts!!!

Post by David Root »

I've used older NOS Sprague 6PS caps with success, 40+ years old difilms ie paper/mylar construction. Some say they don't sound quite the same as the Mallory PVC, but I have also seen it stated that at one point both were made in the same factory and were identical but just labeled differently.
At some point they all changed from mylar/paper to 100% mylar, and these are what most people are using now.

The AES 6PS are much newer and there are manufacturing differences from the older ones. But they are all still polyester film. Stay away from the 715/716 or other polypropylene film, they're not right for Wrecks.
When I was a boy I was told that anyone could become President. I`m beginning to believe it--Clarence Darrow
User avatar
bcmatt
Posts: 665
Joined: Wed Jul 25, 2007 9:35 pm
Location: Canada

Re: Caps...Why am I driving myself nuts!!!

Post by bcmatt »

David Root wrote: The AES 6PS are much newer and there are manufacturing differences from the older ones. But they are all still polyester film. Stay away from the 715/716 or other polypropylene film, they're not right for Wrecks.
This!
While totally fine in pretty much any other amp, I've found a big improvement switching to 6PS caps in my Express and Liverpool from 716s.
jferris5
Posts: 27
Joined: Thu May 15, 2008 2:05 pm

Re: Caps...Why am I driving myself nuts!!!

Post by jferris5 »

Thanks for the input everyone. I think I'm going to start with the 6ps and go from there.
User avatar
DaveWell
Posts: 246
Joined: Wed Feb 25, 2009 9:59 pm

Re: Caps...Why am I driving myself nuts!!!

Post by DaveWell »

Hi
I personally stay away from polypropylene... for an Express. Polyester is the way to go.
CDE6PS or CDE225P is a mimic for the Original Mallory

I would recommend to ask Rooster on the forum, he got the original Mallory coupling caps.
You can't go wrong with that ;)

Dave
Last edited by DaveWell on Sat Dec 31, 2016 4:13 pm, edited 2 times in total.
User avatar
TUBEDUDE
Posts: 1656
Joined: Thu Jan 04, 2007 5:23 pm
Location: Mastersville

Re: Caps...Why am I driving myself nuts!!!

Post by TUBEDUDE »

The 716 and 715 caps pass highs easier. Using just those through the entire amp can make some amps sound strident, bright, harsh or peaky. On those amps, mylar tapers off the highs a little, making the amp a little better balanced. On a dull amp, some 716's will open it up. Wait till you mix n match caps throughout the circuits, like tube rolling, shapeing the response.... welcome to the dark side...we have cookies.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
User avatar
rooster
Posts: 1616
Joined: Wed Apr 02, 2008 8:50 am
Location: Pacific NW

Re: Caps...Why am I driving myself nuts!!!

Post by rooster »

But........ 8)

Originally, when I built my first Express I bought a set of PVC Mallorys from Allyn for $22. I built the amp per guidelines here but found it not the greatest amp I had ever heard..... So I starting swapping different brand/type caps and thought things sounded better. Then I ran into an Alan Phillips Express clone that a friend owned. He payed $5K for it. I thought it sounded very good, and better than my version. :P I called Alan and we had a few conversations, he was very helpful and a nice man, he even offed to voice my amp, which was super nice of him.

However, you know how it goes, you want to solve the riddle yourself. So I kept at it, having now heard what I considered to be an 'in the ballpark' sounding Express. I built a few more Expresses and tried a variety of changes, notably transformers and bias settings. Ppl liked them, I thought they sounded good.

But I still ultimately wasn't completely happy with things. I started to consider the tubes more. I contacted Gregg Levy of Hi Test Guitars, a friend of Ken's back in the day, and he gave me an education about tubes, and also about the biasing of the power tubes.. I picked up some of these suggested tubes and realized I had missed something by ignoring the obvious - tubes and bias settings are important in any amp but maybe more so in an Express.

So, after this education and now running with $500 worth of tubes for the Express instead of $100, I realized I had to go back to square one. The obvious was the caps and I started there, back to the PVC Mallory caps. The change was immediate and remarkable. I then had my friend who owned the Phillips Express clone come over and hear one of these Expresses (I have two). Haha, he said he still thought his had a better grind and bloom to it (!!) and we agreed that he needed to bring his amp over and do a proper shootout. A few days later he brought it over and we got into it. Note, his amp had a pair of Siemens EL34s in it that were biased at 44mAs while I was running Mullards single getter xf4 at 28mAs. After just one back and forth, plugging a Strat into either amp, his facial expression took on a confused look and I felt immediately relieved for having spent so much $$ on tubes. I suggested we change his bias point and he was all in. So we changed it to 34mAs and his amp sounded much better, actually more like mine, although we both felt that mine had a leg up, probably tubes. At this point, while we had the chassis exposed, we talked about a few orange drop caps that were different than what Ken used. (We knew this already because I had studied this amp before - but his thinking at that time was that the amp sounded great even if the caps weren't exactly correct so don't change anything.) Now he said to go ahead and change these three caps just to see if it made a difference, that I would put them back in if we couldn't hear a change for the better. And there was a difference, an improvement we could both agree on. So we left it like it was, wrapped it back up and then played for about an hour, going back and forth between amps. Both amps that we A/B'd (his and mine), BTW, were running Pacific OTs. Both amps were very close to 400VDC on the plates. (BTW, my other Express has a custom Heyboer OT in it, something that Phil came up with, and although it sounds remarkably similar, I didn't want to skew the A/B process.)

So there you go, there's my story about me and the Express. The short of it is, for me, I was very lucky to run into this clone as a basis for comparison, and lucky to have made the (Gregg Levy) connection that caused me to try the tubes Ken actually preferred for his circuit. (Footnote: Alan had made the Express clone for a customer who had an original and didn't want to take it out for live play as the amps were increasing in value. I should also note that Premier Guitar mag had a shootout of some original Expresses that - to me - sounded like ass - something I do not understand except to say the guitar player just did not understand the circuit. Also, to date, Glen's demo is really the best I've ever heard of an Express working like it should and being played by someone who understands the circuit. Peace.
Last edited by rooster on Sat Mar 04, 2017 11:56 pm, edited 1 time in total.
Most people stall out when fixing a mistake that they've made. Why?
jferris5
Posts: 27
Joined: Thu May 15, 2008 2:05 pm

Re: Caps...Why am I driving myself nuts!!!

Post by jferris5 »

Great story thanks for sharing Rooster!
User avatar
RJ Guitars
Posts: 2662
Joined: Tue Nov 14, 2006 3:49 am
Location: Los Alamos, New Mexico
Contact:

Re: Caps...Why am I driving myself nuts!!!

Post by RJ Guitars »

I was lucky enough to buy large bunches of the PVC caps as they became more rare... Actually got the last big batch from Rooster. I think they are really an easy way to know your amp will sound great if you have everything else right... but I leave room for other caps to make that happen if you want to work at it. Tubes matter a whole bunch for sure.

My personal experience is that the best sounding Express I ever heard had Mercury Magnetics iron in it... as well as PVC caps and a really nice set of $500 EL34s. So it's critically important to know that nobody else can tell you what sounds best to you. It's kinda like what flavor of food you like or which sunset looks the coolest. YMMV. rj
Good, Fast, or Cheap -- Pick two...

http://www.rjguitars.net
http://www.rjaudioresearch.com/
http://diyguitaramps.prophpbb.com/
User avatar
DaveMon
Posts: 39
Joined: Tue May 01, 2012 5:17 pm
Location: Burleson, Texas

Re: Caps...Why am I driving myself nuts!!!

Post by DaveMon »

I really enjoyed reading this........there was a wealth of knowledge to be gained here........both in the actual facts stated, and also "between the lines".........by that I mean........I learned that it's ok to justify a 500$ pair of tubes :o .....and that it's most fun to solve problems that you created.....yourself!
User avatar
RJ Guitars
Posts: 2662
Joined: Tue Nov 14, 2006 3:49 am
Location: Los Alamos, New Mexico
Contact:

Re: Caps...Why am I driving myself nuts!!!

Post by RJ Guitars »

DaveMon wrote: Thu Mar 02, 2017 10:01 pm I really enjoyed reading this........there was a wealth of knowledge to be gained here........both in the actual facts stated, and also "between the lines".........by that I mean........I learned that it's ok to justify a 500$ pair of tubes :o .....and that it's most fun to solve problems that you created.....yourself!
That is a great line about solving the problems you created. Failure always leads the way to success...
Good, Fast, or Cheap -- Pick two...

http://www.rjguitars.net
http://www.rjaudioresearch.com/
http://diyguitaramps.prophpbb.com/
Post Reply