The heatsinks were found on aliexpress and were pre drilled for some other chip. I wasn't sure how much dissipation I would need for the regulator and I also wanted something of reasonable size for mounting to the base.
There is a limited number of diodes because of mounting them along the edge of the bracket. I'm wondering about using a 2-3ohm wirewound either before or after the diode string to adjust voltage. Is 6V too low and should I be aiming for 7-9V?
There is a limited number of diodes because of mounting them along the edge of the bracket. I'm wondering about using a 2-3ohm wirewound either before or after the diode string to adjust voltage. Is 6V too low and should I be aiming for 7-9V?
Higher voltage is better, I think. But you can lower the anode voltage to optimise the current, or add the low value resistor.
Hi
i have just made an update on my Rod Coleman reg,,from v7 to v9.. on my 4P1L pre,, and same time i change my TDK pot to a Khozmo shunt relay pot 64steps
it is easy to hear that the new v9 reg is more noise free,, more clean ,more dynamic ,more punch in the 18" woofer
all in all a very nice upgrade to my 4P1L pre
Best Bjarne
i have just made an update on my Rod Coleman reg,,from v7 to v9.. on my 4P1L pre,, and same time i change my TDK pot to a Khozmo shunt relay pot 64steps
it is easy to hear that the new v9 reg is more noise free,, more clean ,more dynamic ,more punch in the 18" woofer
all in all a very nice upgrade to my 4P1L pre
Best Bjarne
A few weeks later please report if you like Khozmo better than TKD.
I prefer conductive plastic potentiometers (for example Noble, TKD ones) than another volume converters ... except TVC/AVC.
I prefer conductive plastic potentiometers (for example Noble, TKD ones) than another volume converters ... except TVC/AVC.
Rod is getting very good feedback for the V9. I think he's rather happy with his work!
He's been designing and redesigning his regs for over 10 years now.
euro21
I have played about 50 hours on the upgrade,, and i must say i prefer the 'khozmo , and the remote is really good
I have played about 50 hours on the upgrade,, and i must say i prefer the 'khozmo , and the remote is really good
It's also rock solid, less drift as it's warming up & with mains voltage change, big step up in sound from V7 imho
Did you fit 100K or 47K? Ale mentioned that 47K may sound better (top end extension), but I've yet to try it, I'm a bit concerned regarding the load of what's upstream, I also have tried Pot(Alps Blue & TKD) & Khozmo, but ended up fitting my own Shunt Attenuator based on Blore Edwards Switch using takeman MF Resistors, the only reason I did that was because the contact wiper on the Khozmo came loose a couple of times (they are a pain to take apart & fix), but mine is an early one & has seen better Days, they look much better made now though!
my Khozmo is 25K with takman REY and Zfoil resistor ,,it look like this but with double so many relay
https://khozmo.com/relays/shunt2a.jpg
and yes, the new Coleman v9 is more stable,
https://khozmo.com/relays/shunt2a.jpg
and yes, the new Coleman v9 is more stable,
Regarding volume control:
1st AVC
2nd Shalco with Vishay Dale RN60-65
3rd Elma with Vishay Dale RN60-65
Still not use the Rod's Coleman V9 but surely be a very good product & Rod's is a very helpfull & kind person.
1st AVC
2nd Shalco with Vishay Dale RN60-65
3rd Elma with Vishay Dale RN60-65
Still not use the Rod's Coleman V9 but surely be a very good product & Rod's is a very helpfull & kind person.
I'd like to use the Khozmo with remote in the BA3- preamp. But I'm stumped on how to provide the 5DCV needed to run it. Can you shed any light on how you did it? Much thanks.
Thanks Andy.. Do you find you like the 2P29L better in this app as a linestage?
It all depends what you are trying to do. I don't use a preamp normally - I feed my 6C4C SE amp directly from my DAC. So my 6C4C amp is 2 stage and uses various IDHT triodes with a mu of 30 or more. I don't need power in a smallish room, I can do with 3W. So in this setup I have no need for a 4P1L or 2P29L or 10Y, 46, 47, 01A or any other DHT because their gain is insufficient. That's the same old story with 2 stage 300b and 2a3 amps.
But if I did want to use any of these admittedly wonderful triodes it would have to be in a 3 stage amp. This could be all-DHT but that's a lot of work. The gains might be worth it - it depends what time and resources you have to put into your experiments.
If you're tossing up between 4P1L and 2P29L I think it's close, and both can easily be used in filament bias. 4P1L has certain nice things about it at 30mA, but I find the midrange a little hollow. 2P29L sounds more neutral to me but doesn't quite have the treble sparkle of the 4P1L. If you have access to 10Y, 46 or 47 I'd use those. For a preamp I'd use a 2a3 or 6C4C.
2P29Ls are low cost, so if you are in doubt, try those to begin. The transformer for B+ is not too big for these, either.
You can power the filament with a low cost EI dual-bobbin 14V 50VA transformer from your local industrial supplier and my new V9 regulators.
With these power supplies, you can experiment with 01A, 26 or 2P29L (one or two resistor changes) and hear the qualities of this wide range of tubes.
Variations on the Siberian circuit can accommodate these too, with different filament bias resistor (filament bias is excellent for all these)
You can power the filament with a low cost EI dual-bobbin 14V 50VA transformer from your local industrial supplier and my new V9 regulators.
With these power supplies, you can experiment with 01A, 26 or 2P29L (one or two resistor changes) and hear the qualities of this wide range of tubes.
Variations on the Siberian circuit can accommodate these too, with different filament bias resistor (filament bias is excellent for all these)
What the man said. All these DHTs need Rod's regulators. I haven't heard the 2P29L with the V9 yet, but I'd be very curious to do so. Should sound very nice. Could be used with gyrator, plate choke or just a resistor load. Filament bias is pretty easy to set up.
Thanks Andy, for the detailed response.. I do have some 801A’s. Do you think they will bias the same in a 10Y preamp circuit? I only know that they are basically uprated 10Y’s..
I may have time to borrow a friend’s 4P1L preamp in a week or so to get a handle on them..