B1 with Korg Triode

Yep, sure, one half each of 2 stereo pots does the trick... it is just more expensive and the Alps won't sound as nice, but no drama, it is an OK pot.
It's okay about the price difference being a little more costly, Claude. Just want to make sure that setting this up with two volume pots was not going to induce any extreme negative consequences to the Mr. Pass's overall Korg design.
@Benjisan
What you will have to do is marking on front side to position the pots to the right value (or whatever you call).
I think that this volume stereo pot is intended for volume regulation. If you think that you will adjust level by your ear you destroy somebody's musical performance.
Not all music have equal level on L & R channel. With stereo pot you adjust divided value by single turn. Don't care about absolute value of the pots, they will divide signal pretty close.
I do understand your point Pitbul.

Unfortunately my brothers hearing loss in his left ear is already making the intended music presentation out of whack for him as the primary listener. So correcting the imbalance by marginally increasing the decibels on the one channel corrects for his hearing deficit; and unfortunately puts other listeners in the room at a disadvantageous position listening wise as the skewing to one channel becomes rather obvious to an individual with better than optimal hearing, than him.

I know this for a fact when I visit him and can plainly hear the increase (shift) to the left channel.
 
I don't know if it was mentioned but this is the exact one that the store uses:


post #6:


Glassware seems to have some cool stuff but they are out of stock of a lot of things:

 
I don't know if it was mentioned but this is the exact one that the store uses:


post #6:


Glassware seems to have some cool stuff but they are out of stock of a lot of things:

Thanks Mike,

I only asked because I was going through some old electronic parts stash and came across a 100K Alps pot that looks very similar in shape and size. I can safely conclude that the 50K and 100K are an obvious mismatch for the intended purposes of using a separate dual L&R volume pot.
 
IF, and that's a big IF, fiddling with 2 pot knobs should be too complicated, and the hearing imbalance constant, then you could also look into some MUTE schematic to dampen one of the channels with a fix value of -X dB.

100k pot, 50k pot, all this doesn't make any difference in real life to the attenuation... it has more to do with the load seen by the stages around of the pot (input and output). Say that for most of our cases 100k pot imposes less constraint on the source (high impedance, easier to drive), at the cost of marginal more noise (all things being equal)... and of course more output impedance which can or not be a problem depending if you have a buffer stage etc..
At the end of the day, most modern sources can drive loads between 10k and 100k anyway...

Have fun

Claude
 

sthcoaster

Member
Paid Member
2016-03-03 9:46 pm
Washington DC
Another Korg B1 success. Great fun.

P2P wiring for the inline filter - fits neatly there on the side (just need a couple of standoffs to mount it properly)

Was able to source unused sliver front kit from fellow DIYA member on swap forum because I had no patience to wait for DIYA Store restock.

Currently teamed with Nobosound D class amp at my temp home in DC, so looking forward to getting it home to UK next year to try it with my ACA and other amps.
 

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rmpfyf

Member
2015-12-27 6:28 am
Another Korg B1 success. Great fun.

P2P wiring for the inline filter - fits neatly there on the side (just need a couple of standoffs to mount it properly)

Was able to source unused sliver front kit from fellow DIYA member on swap forum because I had no patience to wait for DIYA Store restock.

Currently teamed with Nobosound D class amp at my temp home in DC, so looking forward to getting it home to UK next year to try it with my ACA and other amps.
Nice! Where's the inline filter from?
 

sthcoaster

Member
Paid Member
2016-03-03 9:46 pm
Washington DC

rmpfyf

Member
2015-12-27 6:28 am
Thank you. When they're back in stock I'll order a bunch - what a useful little board.
 
Hello, I’m assuming my PCB with JFETS got lost somewhere in Germany and I’m left with pretty much every other component ready but without the “core” of this build. So I decided to go down the DIM route (Do It Myself) and I have worked out a PCB that should work.
Now…I have about 50 or so J113 and I will attempt to match them myself, however I may be punching above my weight here: do I need to aim for an Idss of ≈ 7mA for Q1 and then use matched J113 in Q2 + a value of R that brings me at or below the 7mA of Q1?
I have searched this thread and the above is what I got (I think…) but I’m also wondering if the 7mA of Q1 can be higher without issues
 
Hi Everybody- building my B1/Korg pre-amp. At Step 43, Photo 2 - and testing both sides of the triode, I get 8.9V (not 9.4). I get 24V at the previous step. Is 8.9V within tolerance or does it suggest a problem?

HA! I have this exact same question, 8.8v on mine. I spent an hour trying to figure out why. thanks for beating me to the question.
 
Last time I checked, eons ago, zeners were having broad tolerance. Somewhere in thread I posted, either for fun or someone asked (and I had fun), arrangement with voltage reg in place of zener.
Not saying it's better, maybe just one stumbling step less for Greedy Boyz. So, outa with series resistor in front of zener, then zener, and put 7809 instead