cheaper coupling caps on a budget

my amps started life with m-caps 2.7 value. I sent them to rogue for upgrades [ before there was an official m180 upgrade] they came back with cheap polystyrene caps bypassed with mundorf mcap supreme .47 value. did not like the sound, shure it was more extended in the highs and lows, but it lost the midrange warmth and smoothness it had before . after speaking with some experts in the industry the consensus was that the bypassing of two very different caps was not optimal for better sound. out came the caps ,this time replaced by a single mundorf supreme 2.2 value, this was much better than the bypassed caps, but I could hear less bass from my system. so I don't know if I should bypass the 2.2 value with other mundorf supreme .47 value, or try a different cap all together , there is an issue with space inside the amps. This has opened a can of worms for me, because now I realize just how much caps effect the sound. I dont want [and cant afford] to try all of the different caps out there.

If a cap is a little brighter,it may sound like its lacking in the bass.It would be nice if they had affordable diy test gear to see the results too.One thing about paralleling caps I've experienced years back was the signal may follow the path of the smaller value cap.There is nothing to back this up,but it happened to me with electrolytic caps in parallel when I was taking an electronics course.The teacher said this can happen sometimes,but you never read about it.Doing this with different brands of coupling caps may give all kinds of results.I have an old tube amp with speed clip connectors on it just to get an idea of the different sonics to see if is good enough to try in the better amp.I definitely know about the cost of the caps too.Solen are about the cheapest and sound good in some amps,boring(less musical) in others.I
heard a triode amp that sounded awesome with them in it.I don't like the idea of paralleling them,but have seen it done in amps from the factory.I can't remember the brand though.Going up to 3.0 may work,or be a little bass heavy?The Solen most of the time seem neutral,but still may sound a little lifeless.They are cheap in compare to the others though.An other problem is if you ask 10 different people about the results they got,you may get up 10 different answers.People do sell used caps too.I guess they go through the same as yours and my trials to get what we want.I looked at some V-Caps,$500 each.Yikes!The wrong value anyhow.I hope you end up with something to your liking without going broke.

This place has decent prices on Solens,but I never bought from them.That is about the only 2.7 I see there.[http://www.percyaudio.com/Catalog.pdf]

Chrissain, if you search the web, you'll find all the tube techies say:

"Changing the coupling caps to smaller values reduces bass, while changing to larger values adds more bass."

I recommend getting closer to the original value (2.7 uF). I understand you can't fit a large cap in the chassis which is why you went with 2.2, but this is probably causing your bass problem. You should have eight .47 M-cap Supremes laying around that you pulled out. Solder them in parallel with the 2.2 so your total value comes to 2.67. You don't have to buy anything to find out how it sounds. It might solve your problem.

If you want expert tube mod advice, contact Jim McShane. He's very well respected and a pleasure to work with.

Best of luck with your project!

Since you have the others,try paralleling.You do sound like you have anything to loose.It may get you back into music for now,or may sound good.