They should work alright as the circuit is. Id mA is fixed and will be forced by J3.
DCG3 with AVC
DCG3 sounds really good followed by a Slagle AVC.
I played my balanced unit in SE so as to get a SE out and connected it to my AVC. I turned my stepped voulume attenuator at the DCG3 input to max where it is out of the picture. SE output connected to AVC.
Really surprised! I have to say that this has given me the best tonal balance and dimensionality from the DCG3, better than in balanced mode. I suspect the low output Z of the DCG3 suits the AVC.
Thanks. nash
DCG3 sounds really good followed by a Slagle AVC.
I played my balanced unit in SE so as to get a SE out and connected it to my AVC. I turned my stepped voulume attenuator at the DCG3 input to max where it is out of the picture. SE output connected to AVC.
Really surprised! I have to say that this has given me the best tonal balance and dimensionality from the DCG3, better than in balanced mode. I suspect the low output Z of the DCG3 suits the AVC.
Thanks. nash
Why not use the AVC as attenuator in front of DCG3 ? Maybe too much hassle because of the connections involved ?
Savvas, I was just going to post about this but you beat me to it.
I have tried it but to my ears it sounds better after; I wanted to ask Salas why that could possibly be the case? I was thinking that it could be because the output impedance of my CD player is around 200r while the output impedance of a SE DCG3 is 50r it matches better? Maybe placing an AVC after reduces noise further and therefore sounds better?
There are two DCG3 boards in my balanced unit and by a switch I short out to G the - phase input of each board which leaves me an output only on the + out of each board which is signal referenced to G as out. Salas, any problem keeping the other half of each board powered up and doing nothing with nothing connected to its output?
Thanks. nash
I have tried it but to my ears it sounds better after; I wanted to ask Salas why that could possibly be the case? I was thinking that it could be because the output impedance of my CD player is around 200r while the output impedance of a SE DCG3 is 50r it matches better? Maybe placing an AVC after reduces noise further and therefore sounds better?
There are two DCG3 boards in my balanced unit and by a switch I short out to G the - phase input of each board which leaves me an output only on the + out of each board which is signal referenced to G as out. Salas, any problem keeping the other half of each board powered up and doing nothing with nothing connected to its output?
Thanks. nash
No problem keeping the other half idle.
As to why you prefer the (particular?) AVC aft than fore I don't know. Takes to have some comparative measurements. Noise and bandwidth or even THD maybe differ. Good thing is you found a way to use both and singing. Expensive pot, its a shame not to serve in the system.
As to why you prefer the (particular?) AVC aft than fore I don't know. Takes to have some comparative measurements. Noise and bandwidth or even THD maybe differ. Good thing is you found a way to use both and singing. Expensive pot, its a shame not to serve in the system.
I got enough wiring done last night to hook the DCG3 up to the main rig this morning. I've designed a tiny relay/pilot light controller board that will mount to the front panel, but have yet to send out the files for fabrication. (I will use a bi-color LED for a nifty turn-on mute indication). For now, I energize the relay with a battery.
The left channel input wires are long to give me more room to work when the sub-panel is off the chassis.
Not to sound like a, um, broken record, Salas, but I'm very enthusiastic about the performance. Consistent with other people's reports, it sounds clean and transparent with strong bass drive and effortless handling of percussion.
In addition to the virtues of the DCG3 circuit itself, the Super Regulator and SMD attenuator seem to synergize well with this setup.
It's also so damned cute in this form factor.
My other preamp is an Aikido built with stock Broskie boards. I haven't done a side-by-side comparison yet, but the DCG3 seems like a real cut above the tube unit.
The power amplifier is an "AAK SymAsym" from diyaudio.com about ten years ago. This is also a very nice amplifier.
When I get the timer board done, I will install the decorative front panel. Though the bare front has a kind of cool industrial look to it...
The left channel input wires are long to give me more room to work when the sub-panel is off the chassis.
Not to sound like a, um, broken record, Salas, but I'm very enthusiastic about the performance. Consistent with other people's reports, it sounds clean and transparent with strong bass drive and effortless handling of percussion.
In addition to the virtues of the DCG3 circuit itself, the Super Regulator and SMD attenuator seem to synergize well with this setup.
It's also so damned cute in this form factor.
My other preamp is an Aikido built with stock Broskie boards. I haven't done a side-by-side comparison yet, but the DCG3 seems like a real cut above the tube unit.
The power amplifier is an "AAK SymAsym" from diyaudio.com about ten years ago. This is also a very nice amplifier.
When I get the timer board done, I will install the decorative front panel. Though the bare front has a kind of cool industrial look to it...
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My OPA1656 is installed. For my surprise, no adjustment was required. It was at 0 DC already. It is hard to judge if my sound changed since my unit ran amazingly nice before and after. However, I do see obvious change in DC offset stability. It is dead on 0v and has no even small fluctuations now. BOM OPA always moved a bit +/-. This one is locked on 0. I like it and it is a keeper!!! 
It takes same short listening session op-amp swap to better say about tonal and clarity details. You chanced on a perfect pair of 1656 channels regarding offset but its generally very good in spec anyway.
Next I want to try is ADA4625-2 given a chance. Another super chip, Analog Devices this time. Not as economic as the 1656 though.
Next I want to try is ADA4625-2 given a chance. Another super chip, Analog Devices this time. Not as economic as the 1656 though.
I have (I had once) perfect pitch tested during my parents attended to push me through music school. However, I have very short tonal memory. If it would be ON/OFF switch between OPAs, then I’ll hear difference immediately. 30 sec swap time and off/on circle is long enough timeframe for me to get some nuances and differences.
