The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
Looking for advice on recapping...
Old 28th December 2006
Gear Maniac
c.gymer's Avatar

Looking for advice on recapping...

Hi folks! Long time lurker, first time poster etc.

First up I've done some searches both here and elsewhere and not come up with the info I'm looking for so I was hoping some of you knowledgeable folks could lend an ear and give an electronics newbie a hand?

I've got a Soundtracs PC Midi 24 that is in pretty good condition and works fairly happily with no major quibbles. The desk is over 20 years old now so I've been thinking about a possible recap of both the board and the PSU as this has never been done.

My question is this: if it's worth recapping, then which caps should I be replacing? There are some 50 or so caps and I'm a little confused (to say the least) over which ones should be replaced. Am I looking at replacing just the ceramic caps, or perhaps just the caps on the input/output sections? Or should I bite the proverbial bullet and recap the whole thing?

I'm no electronics wiz, but I do have a (very) basic graps of the concepts of what certain parts are and how to see if there is a physical problem with them, so please be gentle!

Also, would it be worth swaping out the Alps faders for P&G?

Thanks for everyone's time and patince in advance!

Old 28th December 2006
Lives for gear

only the electrolytics... those metal tube lookin ones... start with the power supply... then the master section.... at that point take stock of what's changed and whether to go further... if so then do what you consider to be the worst channel and compare to the rest... you see you may find that what you like about it is the way some have drifted one way and others more deliteriously...
Old 28th December 2006
Gear Maniac
c.gymer's Avatar

Thanks dementedchord, that REALLY narrows things down!

Now, to the RS website for a little spendy spendy...
Old 28th December 2006
Gear Maniac
Bassace's Avatar

dont spendy spendy more than the board is worth
i used one of these at one time ..the psu is the weakestlink
good luck
Old 28th December 2006
Gear Maniac
c.gymer's Avatar

The UK value of this is around £600-700 depending on condition. I paid £300 a couple of years back. They go on ebay every now and then for around £400 but they've never seen a soldering iron since they left the factory!

I won't be throwing more than £150 or so at her though, unless I swap out all the faders for P&Gs as I've got a line on some surplus ones that were kept around as spares.

Thanks again all.
Old 2nd January 2007
Lives for gear
i think your initial upgrade expense should be the opamps. I also have a MidiPC24 that I've had since the 80's. Since I read a previous thread, I decided to do some testing of opamps, to see how much of a difference it would make. Bought some LT1359 quad amps to replace the TL074's and LM4562 to replace the NE5532/TL072's in the master section.

Started out by replacing the opamps in the Master Section. Listened to a CD through the 2-track returns then swapped out the opamps. Listened again and the sound opened right up on both the top and bottom.

Only had two LT1359's left so swapped into IC1 and IC4 locations on Ch 1 I/O module then compared the sound with a mic source and a line source with the adjacent module. It opened the channel up as much as the Master section. It makes the micpres very usable. Also installed the .1mF bypass caps at each IC socket. Still need to replace IC2, for the EQ, but don't need to replace IC3 because it is just driving the LEDs and switching. On the one channel, they didn't seem to have any problems with oscillation so I left the feedback cutoff caps at 47pF.

The LM4562's are about $5US and the LT1359's can be purchased directly from Linear Technology, with a credit card, for $8US. They are expensive, but I would definitely do that first, followed by the interstage electrolytics. You can go ahead and replace the power supply caps and the power caps on the individual boards, which are only 4 per board, at minimal cost. Both opamps were great recommendations by Jim Williams.
Old 21st January 2007
Gear Head

Hmm, that DOES sound interesting....
I can locate the tl074cns on the channel strips fine, but am unable to find the master tl072s/NE5532 on the master section... maybe mine have been switched out with something different already? I am no electronics geek, so....
Could you help me locate them?

Ah found them..

Last edited by eirikur; 21st January 2007 at 07:24 PM.. Reason: Going blind, probably...
Old 22nd January 2007
Lives for gear

while i see nothing wrong with swapping out some opamps... to suggest that it's the best place to start and/or will be more beneficial to a board with 2o yr old caps is just plain wrong.... ok IMO....
Old 22nd September 2011
just want to bump this thread to see if anyone else has recapped their soundtracs .. i have a SOLO, it's in mint condition, sat in a warehouse for years. looks brand new .. wondering if recapping would improve the sound or if i should leave it stock .. "if it aint broke" comes to mind ..
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.

Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Similar Threads
Thread Starter / Forum
hammer / Geekslutz Forum
Bump Music / So Much Gear, So Little Time
labman / High End
inlinenl / Geekslutz Forum
pw8888 / Geekslutz Forum

Forum Jump
Forum Jump