Hey guys,
I finally got some transistors for my tone board, I put 2 new ones in on the left channel (the 403 and 408, I believe they were the pnp set) (the one with problems) and the bass appears much closer. The tonality of the midrange is very different at the moment, but since the bass returned I am gonna bet a total swap of all transistors will result in a match, finally, although I will finsih the left side first to ensure it will sound OK, the right side (the working side) sounds so good I hope it gets to that.

I have run into a snag though, apparently I did something to cause the treble pot to make static when turning when the system is on and its pretty scary, I checked solder joints and I didn't see anything immediate. Anybody have any idea? Its not dirty, its an electrical contact issue it seems.

Anyway, what do you guys think?

Is it static or more of a "whooshing" sound?

It may be an open ground. It could also be a shorted coupling capacitor (these are both causes of a "whooshing" type noise).

DH

Hey guys,
I finally got some transistors for my tone board, I put 2 new ones in on the left channel (the 403 and 408, I believe they were the pnp set) (the one with problems) and the bass appears much closer. The tonality of the midrange is very different at the moment, but since the bass returned I am gonna bet a total swap of all transistors will result in a match, finally, although I will finsih the left side first to ensure it will sound OK, the right side (the working side) sounds so good I hope it gets to that.

I have run into a snag though, apparently I did something to cause the treble pot to make static when turning when the system is on and its pretty scary, I checked solder joints and I didn't see anything immediate. Anybody have any idea? Its not dirty, its an electrical contact issue it seems.

Anyway, what do you guys think?

its not a woosh, its high pitched crackle. I would be worried about tweeters with this problem... hmm
edit- oh and as soon as I make this thing safe, gotta fix this buzz thing, I will measure the left channel to the right and see if the spectrum is right. If so, Ill finish the other channel.

hey so I completed the compliments for the left side and now the entire side is done. whsh, concerning that static.. I have found if I screw in the nuts around the knobs so that they are held tight, and if I touch the bare metal knobs it goes crazy buzz. I dont recall this happening before, but it well could have?

update- i went through the front boards and checked all the wiring, cleaned the backside, and re-tightened and it fixed the buzz. Woohoo. So, either tonight or tomorrow I'll measure the response on both channels to see where things are. On first listen, It seemed the new tranisistors were a bit more neutral with less ~700hz, I will return.

Update- Ok, tested on the KLH model 6, the new channel is much much better than the all-original counterpart, the bass extension is far deeper and the highs are clearer, seemingly less distortion. The dynamics are also much improved, it seemed as though the old transistors shifted things up ever so slightly which made the bass interesting but without the depth of the neutral sound it sounds really bad now. I am greatly pleased by this transistor swap, I will complete the second side shortly and re-compare. If they then match, I think I'll perform this operation on my 2230, the preamp just sounds much much better with the new transistors.

final update- I replaced the other channel with the new transistors, and now both are identical. I think I'll order myself some new trannys for the 2230 now... the noisefloor is so low, and the dynamics/fullness is really really nice. I highly recommend this for anybody doing a recap, do one channel and see if it is better for you, then do the other and enjoy!

final update- I replaced the other channel with the new transistors, and now both are identical. I think I'll order myself some new trannys for the 2230 now... the noisefloor is so low, and the dynamics/fullness is really really nice. I highly recommend this for anybody doing a recap, do one channel and see if it is better for you, then do the other and enjoy!

Can you explain what transistors you changed and what the part numbers were? My 2270 is flakey with bass, and something tells me its more than the caps.

A better sound is always good too!

pm sent!