Thanks Salas
I just recive parts from TeaBag (thanks for GB Tea)
So I have some more questions
...
And for the gain of 2X (as Salas advise) I should use 500R (I recive 1K but will found some 500R some place around
Before I solder everything
would thay work/sound better than what's in kit ?
If thay will/do sound better, should I make some other adjustment to the circuit ? Replace some resistors value ?
As I understand thay are matched in groups 4x8mA, 4x9mA and 4x10mA
( I have 3 x matched quads )
- You can parallel 1K//1K if not having 499R in stock for setting 2X
- 2SK170BL matched quad works too. No other adjustments needed.
Gives more transconductance thus more NFB. The measured THD plunges even lower in the bass and in the mids, something around 0.0002% at 1.2V pk-pk if I remember correctly from when I was testing, but it develops a rising trend towards the highs because that FET also has more parasitic capacitance than the UPA.
Of course THD in the highs is still very low in absolute terms and its alike with the UPA, but the UPA keeps it level with the mids for longer in the highs. That is the technical picture.
Subjectively with the 2SK170BL in the preamp there is even more sense of control and impact while with the UPA there is enough impact but there is more valve like integration in the mid-high. The K170 application seems like having more contrast there but less fluidity.
To my ears and system at least, such things are not guaranteed to be actual and perceivable or just synergistic to other system components such as loudspeakers in a room, so your mileage may vary. Test both types if curious enough since you have them and decide what you like best in your own system.
Hey Salas, I got this Muses Volume control from one forum member: http://www.diyaudio.com/forums/swap-meet/309320-muses-volume-attenuator-kit.html
https://www.dropbox.com/s/qt4uxrzfmxoo8n7/Muses Volume Control English.pdf?dl=0
I am planing to use it with the preamp. Do you think it is ok? I never had any experience with such setup, it requires +/- 15V PSU so I am planing to use some simple LM regulator psu. How Critical do you think is quality of PSU for such volume control and another thing, what do I do with grounds of preamp and Muses PSU? Thank you.
https://www.dropbox.com/s/qt4uxrzfmxoo8n7/Muses Volume Control English.pdf?dl=0
I am planing to use it with the preamp. Do you think it is ok? I never had any experience with such setup, it requires +/- 15V PSU so I am planing to use some simple LM regulator psu. How Critical do you think is quality of PSU for such volume control and another thing, what do I do with grounds of preamp and Muses PSU? Thank you.
I use similar MUSES volume control kit from Japan.
‚l‚t‚r‚d‚r‚V‚Q‚R‚Q‚O�@“dŽqƒ{ƒŠƒ…�[ƒ€ƒLƒbƒg: ‘g—§ƒLƒbƒg �HŒŽ“dŽq’Ê�¤ “dŽq•”•i ƒlƒbƒg’Ê”Ì
I just use the power from one channel of the DCSTB and connect with 2 red leds to drop few volts.
Seanwu thanks for replying to PKI since I have no practical experience with the MUSES. By the way how is your sound now after enough time with the DCG3+MUSES and can you post a build's picture for PKI so he can see the MUSES grounds wiring in the whole preamp configuration?
Thank you Seanwu and Salas.
Yes, pictures would be nice! I will be comparing two volume controls in the preamp: that Muses and r-2r relay based one to chose which one i like better.
I am just not sure if there is any benefit of using separate PSU for volume controllers or it is useless and overkill.
Yes, pictures would be nice! I will be comparing two volume controls in the preamp: that Muses and r-2r relay based one to chose which one i like better.
I am just not sure if there is any benefit of using separate PSU for volume controllers or it is useless and overkill.
I have no idea whether is there any benefit to use separate PSU.
As a newbie, I just use the easiest way to do it.
Thanks Salas for the good design and detailed document. Also thank Tea for the quality kit parts.
Attaches are the pictures of my build. Hope it helps.
Attachments
DCG3 finally boxed...
Some pics of my DCG3 finished today. It took a while, board was ordered on the first GB end 2016...
It use two old SMPS cartridge each providing 30V followed by two linear regulator TL431 based, that allowed using of a small form factor box : a Modushop Galaxy 40mm height.
It sounds very good, thanks Salas and TeaBag !
Some pics of my DCG3 finished today. It took a while, board was ordered on the first GB end 2016...
It use two old SMPS cartridge each providing 30V followed by two linear regulator TL431 based, that allowed using of a small form factor box : a Modushop Galaxy 40mm height.
It sounds very good, thanks Salas and TeaBag !
Attachments
AKG studio cans are nice. Had been used in many professional recordings. Its interesting how some recordings replay best when you know how they were made. I was watching a Youtube video just before, the Pet Shop Boys performing a couple of live songs at a Moscow radio. Everyone in the crowded little studio had Beyerdynamic DT770 on their heads. Including the mixer operator. Was good listening on my Senheiser HD600 but it dawned on me why not give it a go with what I see they wear. So I plugged my DT770. That was it, everything fell into place much better. While the open back Senheiser 600 is a better headphone than the closed back 770 in general, it fell behind on that occasion.
By the way after 48 hours of replay when the preamp's electrolytics will be up for good you may try alternatives like OPA2604 and OPA2134 in the servo position and try listen if they complement your setup any better or not. You have different PSUs so I don't know if the 823 complements as in the rest of builds. Some say they can detect differences between op-amps there, some say no differences.
By the way after 48 hours of replay when the preamp's electrolytics will be up for good you may try alternatives like OPA2604 and OPA2134 in the servo position and try listen if they complement your setup any better or not. You have different PSUs so I don't know if the 823 complements as in the rest of builds. Some say they can detect differences between op-amps there, some say no differences.
On saturday I finally receive Chines aluminum case...
It turn out to be a little small as I didn't have all components in my hand when I was ordering the case...
so...it's compact...low or no heat dissipation...maybe it will melt down
will see, will it do the trick
so this is Jlsounds USB/I2S/AK4490 DAC with Salas DCG3 combo
still in progress...
was thinking to go with jfets K170 but the layout is not design for them, so I would have to band their legs, which is a little complicated
so at the and I'm going with ''stock' version
I have a little desbalanced voltage on power supply on one channel, but Salas say not to worry about it..so I will not...( one side have 18.30 on +/- but the other one have like 18.21 and 18.39 V)...I'm not shure is it 18 or 17V without the load...
So, here are some pictures of work in progress, will get back and report how it sound, once I finish it
It turn out to be a little small as I didn't have all components in my hand when I was ordering the case...
so...it's compact...low or no heat dissipation...maybe it will melt down
will see, will it do the trick
so this is Jlsounds USB/I2S/AK4490 DAC with Salas DCG3 combo
still in progress...
was thinking to go with jfets K170 but the layout is not design for them, so I would have to band their legs, which is a little complicated
so at the and I'm going with ''stock' version
I have a little desbalanced voltage on power supply on one channel, but Salas say not to worry about it..so I will not...( one side have 18.30 on +/- but the other one have like 18.21 and 18.39 V)...I'm not shure is it 18 or 17V without the load...
So, here are some pictures of work in progress, will get back and report how it sound, once I finish it
Attachments
