Ross comp question

[bancika]

Hello,
I've decided to go with Ross Comp with few mods (Hammer's switch and treble recovery mods). I have here two 2N5088's and three 2N5089's. Can I use those three in substitute for 2N5088's? If yes, does it matter where I use 2N5088's and where 2N5089's in circuit?
Thanks in advance

[bancika]

I've just measured hfe for all trannies, 2N5088 are both 510, and 2N5089's are about 500, 520 and 550

[markm]

Hi bancika,
If I remember correctly, trans 3 and 4 (Tonepad layout) are the 2 that people sometimes try to match so, if you used the 5088's there perhaps and the 89's for the other 3 trannies, it'd probably be fine.

These should help
http://www.diystompboxes.com/smfforum/index.php?topic=46861.0
http://www.diystompboxes.com/smfforum/index.php?topic=48582.0

Good luck and have fun by all means!

[bancika]

thanks mark!
will get back with build report

[bancika]

One more question. Today I went shopping for some more parts and they only had 2.5K trimmer. Will it make much difference if I use that one instead?
Tnx

[Mark Hammer]

One more question. Today I went shopping for some more parts and they only had 2.5K trimmer. Will it make much difference if I use that one instead?
Tnx

No.  Given the component tolerances, 2k = 2k2 = 2k5 for the most part.  Same way 47k = 50k and 470k = 500k.

[bancika]

tnx, I've done some changes a'la X47 = X50, but this one was not so close so I was worried (it's 25% higher).
I'll just use that one

[bancika]

Damn those parts, I just found out that I have wrong tappered pots. They are both audio instead of linear. What would be the difference with those?
Shouldn't level pot be audio anyway?
Tnx again and sorry for bothering.

[markm]

Yes,
The level pot should be an audio.
Many like to use a reverse log for the comp control but, my preference is for the regular old linear though.