What feet are those? 🫣
Modushop-chassis?
Yes I would swap those too.
Modushop has some normal-good-looking ones, too. A bit cumbersome to attach them, but absolutely faisible.
I have some modest rubber-feet on mine too, and it got considerably warmer when I put the amp into a closet (front and back removed!), so the airflow is influencial!
Modushop-chassis?
Yes I would swap those too.
Modushop has some normal-good-looking ones, too. A bit cumbersome to attach them, but absolutely faisible.
I have some modest rubber-feet on mine too, and it got considerably warmer when I put the amp into a closet (front and back removed!), so the airflow is influencial!
We are FAB. We aren’t afraid of a little heatWhat feet are those? 🫣
Modushop-chassis?
Yes I would swap those too.
Modushop has some normal-good-looking ones, too. A bit cumbersome to attach them, but absolutely faisible.
I have some modest rubber-feet on mine too, and it got considerably warmer when I put the amp into a closet (front and back removed!), so the airflow is influencial!

The transformers finally made it to destination, next piece of shopping the case but I think I am set there with your advise, since I have a friend coming off the US I was thinking about getting the volume pot if I can find a better deal there but still need you to advise value (50k or 100k), brand and which would better fit considering the construction (dual mono, I-select board and Sigma22 PSUs).
Which of these would fit the bill, Shunt 25K stereo? https://khozmo.com/products_dale_shunt.html
Grazie

Which of these would fit the bill, Shunt 25K stereo? https://khozmo.com/products_dale_shunt.html
Grazie

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You know the Khozmo stuff ships from Poland? They're really fantastic. I've used several of them.
Great to know!!! I emailed them re shipping, what I need to figure is which device would do it without to break the bank and to overdoYou know the Khozmo stuff ships from Poland? They're really fantastic. I've used several of them.
Grazie
It's mostly a matter of preference. The price difference between the various models is not huge. The ladder one is a bit more because there are a lot more resistors. The advantage is that there are only ever two resistors involved. The shunt version has that advantage, too, but it has variable impedence, which may or may not be something you want. I've used the series one myself, and been very happy with it.
So the series one in 25K could fit the bill of my build?It's mostly a matter of preference. The price difference between the various models is not huge. The ladder one is a bit more because there are a lot more resistors. The advantage is that there are only ever two resistors involved. The shunt version has that advantage, too, but it has variable impedence, which may or may not be something you want. I've used the series one myself, and been very happy with it.
If I only had a clue of what would it change from, say, 100k to 25k... Do one keeps it low to minimise noise and high to have a smoother range?I would think so. The impedence is largely up to you.
No idea about the fact, or fiction of which impedance to use.
All I know is that a 10K shunt type works superbly in my system.
(Fed from a Marantz network player into an F6.)
https://www.hificollective.co.uk/attenuators/glasshouse-takman-stepped-attenuator-metal-025.html
All I know is that a 10K shunt type works superbly in my system.
(Fed from a Marantz network player into an F6.)
https://www.hificollective.co.uk/attenuators/glasshouse-takman-stepped-attenuator-metal-025.html
Well, this isn't good.
I have been using my 2nd BA-3 preamp for about six months.
I started to notice that the right channel was weaker than the left. Confirmed that on multiple FW amps.
I opened it up and checked the bias/offset settings for both channels.
Bias for both was 48DCV and offset was ~ 0. That's not good. Bias = 1DCV is the goal.
I unplugged and rolled back the trim pots to 0.
Took new readings and got the same results.
If I move both P1's nothing changes with the bias.
The PSU is delivering 24 DCV. + / -.
No parts looks fried, but something must be.
I appreciate any guidance.
I have been using my 2nd BA-3 preamp for about six months.
I started to notice that the right channel was weaker than the left. Confirmed that on multiple FW amps.
I opened it up and checked the bias/offset settings for both channels.
Bias for both was 48DCV and offset was ~ 0. That's not good. Bias = 1DCV is the goal.
I unplugged and rolled back the trim pots to 0.
Took new readings and got the same results.
If I move both P1's nothing changes with the bias.
The PSU is delivering 24 DCV. + / -.
No parts looks fried, but something must be.
I appreciate any guidance.
Attachments
Chip,
To measure the bias, you measure the voltage across the resistors R11 or R10 individually and not from R10 to R11 (as you seem to have indicated in your photo).
To measure the bias, you measure the voltage across the resistors R11 or R10 individually and not from R10 to R11 (as you seem to have indicated in your photo).
Depth wise, 30 or 40cm? Maybe 40 is too much, slight difference in price but lot more footprint and space is always precious both in and outside.I used this one, plenty of room for a dual mono build.
https://modushop.biz/site/index.php?route=product/product&product_id=154
Top cover standard or grilled for better heat dissipation?
Feet wise, those from ModusShot don't look that great, any hint at where to find better ones? I like 'em round and low, maybe half an inch or so height not to rip too much space in height unless you suggest differently.
Next step will be the volume pot and then RCAs, knobs, power switch (which I'd like to be matching the power amp, a round button with LED light)...
Grazie
Giovanni,
Did you see the links concerning feet I posted a few weeks ago?
It’s an italian house and they have plenty…
Did you see the links concerning feet I posted a few weeks ago?
It’s an italian house and they have plenty…
Yes I saw it, I am actually debating on the depth of the case, either 300mm or 400mm, not much of a price difference but footprint and empty space, my guess is that 2x toroids on the left side, the iSelect on the bottom, 2x Sigma22 in the middle and the BA-3 should have plenty space even within 300mm, maybe I should arrange a quick CAD prototype to find out.Giovanni,
Did you see the links concerning feet I posted a few weeks ago?
It’s an italian house and they have plenty…
This is the case by the way
Grazie
p.s. suggestion for the feet?
I‘ll be using an even smaller (320 or so width) one, with Salas Ubibs insteas of sigmas. Made a floating layout with the parts inside, it’s a bit dense but works. But—of course—don’t rely on me, verify your layout…
Yes the feet, that’s what the link I mentioned was about 🙂
https://www.audiogears.it/category.php~idx~~~55~~FEET+AND+SPIKES~.html
Yes the feet, that’s what the link I mentioned was about 🙂
https://www.audiogears.it/category.php~idx~~~55~~FEET+AND+SPIKES~.html
I used feet similar to these (not sure if they are the exact same ones) to replace those that came with the Vfet chassis:
https://www.ebay.ca/itm/20339133313...HrR8eXJOJ6pQq1rIjRSfC+Ysyzaz|tkp:BFBM0pbc5vFg
https://www.ebay.ca/itm/20339133313...HrR8eXJOJ6pQq1rIjRSfC+Ysyzaz|tkp:BFBM0pbc5vFg
So far, by a quick sketch, it seems 300mm depth won't fit it comfortably, I might have done something wrong but:
- 2 x toroids 63mm diameter
- 2 x Sigma22 boards 150 x 89mm
- 1 x BA-3 board 140 x 70mm
- 1 x I-Select board 160 x 49mm
Move second Sigma for 90 degres and done!So far, by a quick sketch, it seems 300mm depth won't fit it comfortably, I might have done something wrong but:
Of course matter of laying it all out but I wonder if I should go for the extra 10cm depth case...
- 2 x toroids 63mm diameter
- 2 x Sigma22 boards 150 x 89mm
- 1 x BA-3 board 140 x 70mm
- 1 x I-Select board 160 x 49mm
View attachment 1095555
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