It is currently Mon Mar 16, 2020 10:51 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 6 posts ] 
Author Message
Post subject: Silver Mica vs. Ceramic Caps in old Fender amps (revisited)
Posted: Sat Dec 24, 2016 2:46 pm
Offline
Roadie
Roadie

Joined: Sat Mar 09, 2013 12:27 pm
Posts: 207
I know there are other threads on this, but lets get into details. I replaced the ceramic caps in a 72' bandmaster reverb as they were all leaking DC. I had a bag of CDE 250pf/500's so I replaced the treble cap on each channel and used 2 in parallel for the 500pf in the reverb circuit, huge difference in sound. The high end is much more mellow. I actually like it, but I'm amazed a the difference. There are three classes of ceramic. 1, 2 and 3. NPO is in class one, but Fender used class 2 Z5F's in most cases, 7.5% tolerance. Brands and types of capacitors matter and sometimes crappier specs give the tone. Tone is an art. What are the best replacement caps, coupling, electrolytic, tone, for classic Fender tone. Opinions and scientific explanations welcome. Thanks, Krank


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Silver Mica vs. Ceramic Caps in old Fender amps (revisit
Posted: Sat Dec 24, 2016 6:40 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
I've been using F&T electrolytic caps in the PSU. F&T and Sprague Atom caps in the bias supply and bypass. Been very reliable. CE cap cans, for amps with multi-section cans.

As for coupling caps, Jupiter Yellow Vintage Tone, Dynami-caps, & Russian mil spec K40Y-9 have all worked out well, in terms of tone and service length.

Jupiter Red and Jensen PIO for tweed era amps. SBE Orange Drops for earlier woody era amps.


Top
Profile
Post subject: Re: Silver Mica vs. Ceramic Caps in old Fender amps (revisit
Posted: Sun Dec 25, 2016 5:44 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14047
Location: Province de Québec, Canada
BMW2002Ti wrote:
I've been using F&T electrolytic caps in the PSU. F&T and Sprague Atom caps in the bias supply and bypass. Been very reliable. .



+1
I always use them, stay away from Illinois caps ( IC )


Top
Profile
Post subject: Re: Silver Mica vs. Ceramic Caps in old Fender amps (revisit
Posted: Sun Dec 25, 2016 8:22 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26416
Location: Tombstone Territory
stratele52 wrote:
stay away from Illinois caps ( IC )


+1000

The most miserable polliwog in the electrolytic pond.

:lol:

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Silver Mica vs. Ceramic Caps in old Fender amps (revisit
Posted: Sun Dec 25, 2016 12:27 pm
Offline
Professional Musician
Professional Musician

Joined: Thu Aug 07, 2014 3:25 pm
Posts: 1023
Hey Stratle52, Congratulations on cracking 10,000 posts.

While the classic Fender tone partly depends on classic capacitors, you must always remember that these were built as commercial quality appliances. Cost was always a limiting factor. Distortion and noise specs were high. There were no boutique amps to compare with.
They were not building museum pieces to be worshipped by a later generation. They were just building the best amp with parts the market could afford.
Leo Fender was an accountant and paying attention to production costs was just as important then as now.
So ceramic disk caps were the industry standard. Silver mica caps were only used in critical RF applications as they cost 10 time the ceramic equivalent..
With the advent of modern plastics and controlled production atmospheres, higher quality capacitors became affordable for production units. They are mostly used for coupling, bypass and filtering.
The ceramics still out competed the SM in price. Sound was acceptable, so they stayed.
The reason a SM cap sounds better is it is more accurate.
In a perfect capacitor, the charge rate is perfectly linear with time. That is a graph of time and charge voltage would show a single, straight diagonal line for charge and discharge.
In a ceramic capacitor, it has a lag in charging and a lag in discharging. The graph now has a narrow loop showing a tracking error.
With a complex guitar signal, the ceramic cap can't track the incoming signal accutately.
Electrolytic caps are also slow to respond in the same manner.
Poly and SM caps do a much better job of tracking a complex signal. You hear it as crisper, cleaner tone.

So the question I face is whether classic Fender tone has any significant relevance.
Its not a choice of Leo's. Its what he could afford to produce.
If we fast forward to today, do we say that the Hot Rod Deluxe is a sacred circuit and we should strive to maintain them as original as possible? Future generations will condemn us for modified Fender products?
Their guitars will have microwave interferomer cavity amplifiers that will cause the air to vibrate directly in front of it at 2000 watts.
In the meantime, I have no qualms about pushing designs into the future. Leo continued to evolve at Musicman and I'm sure there are some things he made there that are redesigns of his old models with op amps. Heresy from the prophet himself!!
My feeling is that the classic Fender tone is derived from the tone stack. The interacion of the tone capacitors is unique and adds complexity to the tone.
The transformer on the output stage also defines the tone balance and gain characteristics that define Fender models.

Merry Christmas everyone. May your Fenders be bright and to all a good night. here's a couple Fenders in perfect harmony
https://www.youtube.com/watch?v=O9-omfPE2Wk


Top
Profile
Post subject: Re: Silver Mica vs. Ceramic Caps in old Fender amps (revisit
Posted: Sun Dec 25, 2016 12:53 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14047
Location: Province de Québec, Canada
TimsAudio wrote:
Hey Stratle52, Congratulations on cracking 10,000 posts.



I am discovered as addict to the web :oops:

Merry christmas to you TimsAudio and all of forum's members


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: