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Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

Salas DCG3 preamp (line & headphone)
Salas DCG3 preamp (line & headphone)
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Old 22nd November 2019, 01:19 PM   #4171
Salas is offline Salas  Greece
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Salas DCG3 preamp (line & headphone)
You are looking for system synergy details. You have to experience pot Zo differentiation in situ for yourself. My recommendation is try the other options as well. 327s and 2SK170s with series or shunt PSUs. L-Adapter stacked positives are yet another option. A powerful little PSU. It may give the sense you are after with its high Amperage series pass transistor and hi-cap reservoirs.
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Old 22nd November 2019, 01:30 PM   #4172
Salas is offline Salas  Greece
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Quote:
Originally Posted by savvas View Post
My opinion is that although new generation DAC is used, it's still gives a touch of that opa-sound which I'm not fan of.
OPA based for its output circuit indeed if I remember correctly.
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Old 22nd November 2019, 01:58 PM   #4173
Theodosis O. is offline Theodosis O.  Greece
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Originally Posted by savvas View Post
No, for DCG3 I have Panasonic FC. In other circuits I've tried them for local decoupling they open up the soundstage with lots of details. Usually I use them in digital stuff, let's say for special purposes.
After many tests, I found Organic Polymer far more dynamic. More energy.
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Old 22nd November 2019, 07:22 PM   #4174
nashbap is offline nashbap  United States
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Salas DCG3 preamp (line & headphone)
Hi Salas,

You mention that the new boards have split grounds. Why was this done? Also, you had suggested in the past that the ground could be cut. Could you point out where?
Thanks.
nash
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Old 22nd November 2019, 10:30 PM   #4175
savvas is offline savvas  Greece
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Quote:
Originally Posted by Salas View Post
You are looking for system synergy details. You have to experience pot Zo differentiation in situ for yourself. My recommendation is try the other options as well. 327s and 2SK170s with series or shunt PSUs. L-Adapter stacked positives are yet another option. A powerful little PSU. It may give the sense you are after with its high Amperage series pass transistor and hi-cap reservoirs.
I've already tried DCSTB, BIB and UBIB, each with its own sound character. My transformers and not CT so L-Adapter could also be tried although I'm expecting they won't deviate much from DCSTB.

As for pot Zo one option is to buy one or two cheap chinese DACT-clone pots and experiment with different Zo. The biggest problem upgrading my relay-based is finding better spected resistors (i.e. the right values). If I have hard time finding suitable values I'm gonna try Muses solution, it's output resistance is between 1K5 and 6K5.

Quote:
Originally Posted by Theodosis O. View Post
After many tests, I found Organic Polymer far more dynamic. More energy.
Thanks Theodosis, I have another DCG3 for the making indented for balanced and A/B part testing so I could try this along with other things .
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Old 23rd November 2019, 12:01 AM   #4176
Salas is offline Salas  Greece
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Originally Posted by nashbap View Post
Hi Salas,

You mention that the new boards have split grounds. Why was this done? Also, you had suggested in the past that the ground could be cut. Could you point out where?
Thanks.
nash
For flexibility in grounding schemes. A gap can be bridged when a lane can only be cut so better have a gap I thought. Thus I added that feature. Don't cut a classic board except there's a ground loop in a certain system and you need to try alternatives. Which is not that likely since buzz free classic board builds playing in various systems are so many here.
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Old 23rd November 2019, 03:36 AM   #4177
nashbap is offline nashbap  United States
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Salas DCG3 preamp (line & headphone)
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Originally Posted by Salas View Post
For flexibility in grounding schemes. A gap can be bridged when a lane can only be cut so better have a gap I thought. Thus I added that feature. Don't cut a classic board except there's a ground loop in a certain system and you need to try alternatives. Which is not that likely since buzz free classic board builds playing in various systems are so many here.
Thanks. Nash
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Old 23rd November 2019, 03:57 AM   #4178
nashbap is offline nashbap  United States
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Quote:
Originally Posted by savvas View Post
My opinion is that although new generation DAC is used, it's still gives a touch of that opa-sound which I'm not fan of. That being said, my new amp make this shortcoming less obvious. It's quite enjoyable, not tiring at all but not my cup of coffee
I don't want it and neither DCG3 does sound 'balsie' but I'm fan of dynamic sound and that could be improved if I bring my attenuator to DCG3's recommended specs. So is it better to have constant 6.25K or 5K output resistance for attenuator ?

I don't expect big changes and there are other things to play with: I have yet to test BC327s, LSK JFet, etc. The new amp push them back but now tweaking time has come.
Hi Savvas,

Let me suggest another way to address your attenuators question.
Most of us here are serious listeners and do most of our listening in a certain db range. With my dcg3 my normal level is -27db pot attenuation, going down to about -31 and louder to about -19 db. In my case -27db is with 20k and .909k resistors for a pot value of 20.9k. Measure your present pot at your most listened position, then use resistor combinations to achieve that and choose what sounds best. Better still build your own like I do with your favorite resistors.
Nash
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Old 23rd November 2019, 11:54 AM   #4179
savvas is offline savvas  Greece
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Quote:
Originally Posted by nashbap View Post
Hi Savvas,

Let me suggest another way to address your attenuators question.
Most of us here are serious listeners and do most of our listening in a certain db range. With my dcg3 my normal level is -27db pot attenuation, going down to about -31 and louder to about -19 db. In my case -27db is with 20k and .909k resistors for a pot value of 20.9k. Measure your present pot at your most listened position, then use resistor combinations to achieve that and choose what sounds best. Better still build your own like I do with your favorite resistors.
Nash
That's nice solution especially if you are on a budget but you don't want to cut corners.
The problem is that remote is a must for me and this is very costly for switching resistor type of attenuators. Relay-based ones are most cost-effective solution with small number of resistors but with weird values (so those exotic type of resistors can't be used)
Aiming at Dale PTF or something similar otherwise compromise has to be made or simply finish the psu for Muse.
I want to settle with the attenuator thing and then start other tweaks.
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Old 23rd November 2019, 02:57 PM   #4180
nashbap is offline nashbap  United States
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Originally Posted by savvas View Post
The problem is that remote is a must for me

You could be happy with a stepper motor driven stepped attenuator.

nash
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