Doubt it - they're good quality. Low current passing through, so I really doubt you'd notice any difference.
I've changed the output caps to 10uF Obbligato MKP. Seem decent enough, and it allows me to use any power amp.
I've changed the output caps to 10uF Obbligato MKP. Seem decent enough, and it allows me to use any power amp.
Well, in addition to the neohm 50R resistors in the I/V positions, I upgraded about 12 other resistors with a nice quality resistor. I also replaced the coupling caps with Duelund Cu PIO 1 uF coupling caps, which on purchased on sale from Parts Connexion.
I am very pleased with the end result.
I am very pleased with the end result.
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Wow! Beautiful job! What are those tubes - RCA clear tops?
I was playing around with my tubes recently and found a nice combination: Toshiba Hi-S 5963 as input tubes, and Raytheon 12AT7 output tubes. Very clinical sound! 300R MK132 cathode resistors.
I was playing around with my tubes recently and found a nice combination: Toshiba Hi-S 5963 as input tubes, and Raytheon 12AT7 output tubes. Very clinical sound! 300R MK132 cathode resistors.
The tubes are 12AU7A. There made it the US and have a splotch of gray on the side. I am not sure if they are "cleartops". I got them for a buck a piece.
I bought a pcb from Broskie does anyone know what R18,R19 and C19 is for?
If they should be used?
If they should be used?
If anyone is still experimenting with the Unbalancer circuit, I thought I'd post a link to this thread as Ian/Ruffrecords has found a circuit error on the original Unbalancer PCB (the PCB which has the PSU included).
http://www.diyaudio.com/forums/tubes-valves/253273-grid-resistors-gnd-3.html#post3878912
http://www.diyaudio.com/forums/tubes-valves/253273-grid-resistors-gnd-3.html#post3878912
Hello everybody, i'm really excited reading this thread, i can't stand in my shoes waiting to build my B III + Unbalancer DAC!
But i'm 1/2 steps behind you and stuck deeply in finding out how to assemble an Unbalancer even starting from Glass-ware PCB... 😕
Could someone please suggest me all R and C values for an I/V stage Unbalancer for a B IIIse DAC?
I would use JJ ECC802 input and EH 6CG7 output tubes and 2.2/3uF C3 (too much?); a Janus Shunt Regulator to power B+ and Heaters, set to 250/260V and 12.6V.
Just to state one of my problems, i can't figure out R12 correct value to achieve this as i'm not able to quantify the current flow on it. How can i calulate current flow in the Unbalancer?
Thanks to anybody will be so kind to help me!
But i'm 1/2 steps behind you and stuck deeply in finding out how to assemble an Unbalancer even starting from Glass-ware PCB... 😕
Could someone please suggest me all R and C values for an I/V stage Unbalancer for a B IIIse DAC?
I would use JJ ECC802 input and EH 6CG7 output tubes and 2.2/3uF C3 (too much?); a Janus Shunt Regulator to power B+ and Heaters, set to 250/260V and 12.6V.
Just to state one of my problems, i can't figure out R12 correct value to achieve this as i'm not able to quantify the current flow on it. How can i calulate current flow in the Unbalancer?
Thanks to anybody will be so kind to help me!
Nobody can answer?
Come on, you all built a Buffalo III Dac using unbalancer as i/v stage... just tell me the various R and C values you used...
Taking care of the correct tubes specifications, of course... i'm asking too much?
Come on, you all built a Buffalo III Dac using unbalancer as i/v stage... just tell me the various R and C values you used...
Taking care of the correct tubes specifications, of course... i'm asking too much?
Just another question: i see 6n2p tubes need a different circuit layout from 12ax7, as they have filaments on pin 4 and 5 (and 6,3V power).
Could i mount them on Unbalancer as it is or should i implement some kind of adapting mod?
Could i mount them on Unbalancer as it is or should i implement some kind of adapting mod?
Are you sure that it is needed? Reading the Unbalancer manual i see that 6.3V tubes heaters receive power from pins 4 and 5 (if you use a 6.3V power supply), so it should work anyway...
Am i wrong?
Too bad we can't ask Galss-Ware Audio directly: they never answer any mail...
6N2P pin layout seems just the same as 6N1P one to me. So, if 6N1P can be used without mod, why 6N2P can't?
12AX7 pinout is different when used in 12V circuit, but i read they can receive power at pins 4 and 5 too, when used at 6.3V. Is this untrue?
You don't need any mod. Read the manual about jumpers for heaters. It's page 12 in the manual. As for R12, please, check other manuals, Aikido, for example. This RC filter is used in other boards as well. For manuals google.
Thank you, but i'm still a little bit confused about resistors value. I'll find out about R12 values, but i'm not sure about i/v, cathode, anode and CCS resistors for the following tubes i have, to make Unbalancer work well:
- 12BH7
- 6N23P
- 6N2P
I would like to try 30 ohm i/v resistors for the latter, but Broskie's schematic here The Unbalancer shows 34R CCS resistor using 60R i/v resistors: he fears that using 30R i/v resistors, cathode voltage would be too low for CCS to work OK (6N2P has a very low anode current of about 2mA), so what resistors should i use for CCS set and cathode resistors with 30R i/v resistors? 120K for anode is OK?
50 ohm i/v should be OK for 12BH7 and 6N23P, i guess i should use 6.8R CCS and 300R cathode resistors, am i wrong? Then for anode i should stay around 24K for both? Could i lower i/v resistors any more (mostly using 6N23P)?
I will use Unbalancer as a preamp in my system so i would need 2V output at least...
- 12BH7
- 6N23P
- 6N2P
I would like to try 30 ohm i/v resistors for the latter, but Broskie's schematic here The Unbalancer shows 34R CCS resistor using 60R i/v resistors: he fears that using 30R i/v resistors, cathode voltage would be too low for CCS to work OK (6N2P has a very low anode current of about 2mA), so what resistors should i use for CCS set and cathode resistors with 30R i/v resistors? 120K for anode is OK?
50 ohm i/v should be OK for 12BH7 and 6N23P, i guess i should use 6.8R CCS and 300R cathode resistors, am i wrong? Then for anode i should stay around 24K for both? Could i lower i/v resistors any more (mostly using 6N23P)?
I will use Unbalancer as a preamp in my system so i would need 2V output at least...
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The Unbalancer is not an I/V stage when used with the Buffalo, since it's input impedance is far too high.
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