Thanks Zen, so my arrangement should work? I want to have one line with buffer before and after LDR available for some cases, and now I can do that Eg. Elma pz 2 Lorlin pz b
Keep in mind that the Pearl from Pass DIY is the second generation - Pearl 2.
Mine is the first, the original non-inverting pre.
Of course if buying from Pass DIy you'll also get the Fets which are hard to find.
My phono is built on a stripboard with SK369 instead of SK170 (half the number of Fets), and also an output buffer ala B1.
You don't really need a PCB, stripboard works just fine and will fit in a chassis with B1Korg, but do you have the Fets is the main question?
Cheers
Unfortunately, no. I am very new at this. A few weeks ago I couldn't even spell FET and thought Mouser was a synonym for cat.
Pass DIY Addict
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Just finished up the cap replacement in my B1 Korg. I used the film caps that Claude suggested (thank you). While I was at it, I added in the rubber vibration isolation mounts that I picked up on ebay (these are linked in one of my posts above). The rubber mounts reduced the magnitude of Nutube ringing by 15-20dB when I adjust the stepped attenuator. Not gone, but clearly better.
It took a little while to figure out how to arrange the caps so I'd still have access to the trim pots and the Nutube. I used hot glue to hold them in place on the board - it seems to have worked well. Just put it all back together, so I haven't had time to sit and listen yet.
With the new cap values (0.22uF, 1.0uF, and 3.3uF instead of 10uF all around) the -3dB points are about 10Hz and about 65kHz. At 20Hz, response is down just a small fraction of a dB. Since my main speakers (FHLXs) don't really "do" the 20Hz thing, this is a difference I'll never notice.
Looking forward to some time to listen in the coming days!
It took a little while to figure out how to arrange the caps so I'd still have access to the trim pots and the Nutube. I used hot glue to hold them in place on the board - it seems to have worked well. Just put it all back together, so I haven't had time to sit and listen yet.
With the new cap values (0.22uF, 1.0uF, and 3.3uF instead of 10uF all around) the -3dB points are about 10Hz and about 65kHz. At 20Hz, response is down just a small fraction of a dB. Since my main speakers (FHLXs) don't really "do" the 20Hz thing, this is a difference I'll never notice.
Looking forward to some time to listen in the coming days!
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While I was playing around, I also adjusted each channel for a combination of highest H2 with lowest H3. I was surprised by the difference in T7/T8 voltage settings to make this happen. I ended up with 9.8v on the right channel (pretty close to the recommended 9.5v), but it took 10.2v on the left channel to come closest to matching it. With a 1kHz signal and an overall output level of about -10dB (trying not to overwhelm the sound card) I was able to directly match H2 magnitude (at -47dB), but the H3 levels were still rather different. H3 measured -78dB in the left channel and about -97dB in the right channel. I was unable to get the left channel H3 any lower. Guess the individual tubes have a bit of variation to them...
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Thank yoo
Thank you
Christmas batch are Toshiba 2SK370 laboratory matched by Papa so yes they are interchangable. No worry relax
Thank you
Genuine Toshiba is scarce to get.
If in stuffing board rush I do always touch jfets black plastic case but never DGS metalic pins ,
its keept them safe and away from the body skin electricity
Kind regards
Pass DIY Addict
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I measured each of mine. The lowest measured 4.79mA and the highest was 4.91mA, so all were +/- 0.05mA of the median. Thus, they are all well matched and interchangeable. Just put 'em in and enjoy!
