Capacitor help - Quad 303 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 16th January 2014, 05:43 PM   #1
diyAudio Member
Join Date: Jan 2014
Default Capacitor help - Quad 303

Hi, I'm new here so sorry if I've posted in the wrong section.

I'm having trouble finding information on a particular capacitor. It's the four big ones, the two in parallel for the PSU and the two smoothing caps.

The caps are BHC, but I can't find anything about them (Rated lifetime, ESR rating etc, I would just like a datasheet on them).

The markings are: 2200uf-10+50%, 100 VDC, KA 10A 222 T100 FF, UK Made.

And on the top the number reads: 9703

Thanks in advance,
  Reply With Quote
Old 16th January 2014, 08:10 PM   #2
AMV8 is offline AMV8  United Kingdom
diyAudio Member
Join Date: Jan 2005
Location: near london
If you type "BHC Capacitors datasheet" in google you will find a complete (160 page) specification of BHC Caps. If not directly apparant where the datasheet is look under the digikey advert that appears.

In my experience BHC power supply caps are as good as any made. I have never found a faulty BHC cap or even a deteriorating BHC power supply cap when I have measured capacitance and ESR. But it is an older amplifier so it is wise to check all the electrolytic capacitors. Normall the lower value electrolytic capacitors on the pcb are the ones that need to be changed.

As an example, I have just been renovating some C Audio professional power amplifiers from the 1990's that all used BHC 120v 15,000uf power supply caps. The capacitance all measured around 14,500uf and the ESR was in the range of 0.03 to 0.08ohm. They all measure ok and sound ok. But you should check all your caps. However the small value electrolytic capacitors on the pcb's all measued poorly except for some Phillips electrolytic capacitors which still measure better than almost any I can buy today.
  Reply With Quote
Old 17th January 2014, 07:47 AM   #3
diyAudio Member
Join Date: Apr 2010
Location: Coffs Harbour
I don't think the ca. 2006 listing covers older grades such as the OP's or the OEM parts which were TTC or Callins (long gone) products. In 160 pages there are only a few types that are referred to as "long life" or "low ESR" which is pretty vague but normal for general products and specs. made before ~1990. Ripple current rating is a much more likely specification before ESR became an important number for switchmode power supplies.

Check Quad-modder specialist sites like Keith Snook, dada and net-audio for what is offered or recommended now, given that modern equivalents will be small enough to fit caps many times the size at better performance all round. Similar caps to your originals in the same sizes will be unobtanium, so it means adaptation in one form or another.
  Reply With Quote
Old 17th January 2014, 05:11 PM   #4
diyAudio Member
Join Date: Sep 2006
Older capacitors tended to have higher ESR and ESL than newer ones. To replace them you only need to look for 2200 uF (2.2mF these days) 100V and check the new suppliers ESR and ESL, and ripple current rating. Normally newer types can handle higher currents than the older ones. Probably smaller too so you will have to replace the clamps.BHC now appear to be Kemet. 2200uF is rated at 4.9A ripple, 69milliohms resistance, 55 milliohms at 10kZ. Should do the job.

  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Quad 303 recap Piccolino Solid State 4 30th May 2014 09:50 AM
Quad 303 Upgrade - How far is too far? HiFiWill Solid State 13 28th March 2013 02:19 PM
Quad 303 problem Intheloft Solid State 2 17th April 2010 01:57 PM
QUAD 303 transistors TonyF Solid State 17 14th September 2004 02:23 PM
Quad 303 screws cpu_bach Solid State 6 4th August 2004 01:42 PM

New To Site? Need Help?

All times are GMT. The time now is 04:26 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2