My Korg has just got into service together with M2X. I switched preamp from Starving Student II which sounded really good. I must say that after some hours of listening to Korg it sounds as least as good. I might prefer the Korg.
At initially setup I thought I had found the must silent combination ever until I found out that input was connected to input and output to output.
Regarding grounding to chassis I only use the "native" from the mounting holes on PCB. I have no noise problems at all with 94 dB speakers.
I has been able to dampen the chassis so I can knock on the chassis without any sound in speakers. I think compared to a real tube pre or power tube amp the Nutube is easy to handle regarding "microphony". E.g. Starving Student II is more sensitive but works very well in "real use".
At initially setup I thought I had found the must silent combination ever until I found out that input was connected to input and output to output.
Regarding grounding to chassis I only use the "native" from the mounting holes on PCB. I have no noise problems at all with 94 dB speakers.
I has been able to dampen the chassis so I can knock on the chassis without any sound in speakers. I think compared to a real tube pre or power tube amp the Nutube is easy to handle regarding "microphony". E.g. Starving Student II is more sensitive but works very well in "real use".
I am sure the Elna is ok for this purpose. I have tried electrolytics several times and the sound is ok because off the dc on them. If not I would not use them. And never for more the aprox 15 vdc. More then that and there will be dc after them. And I can not explain why.
Of course, electrolytics do their job, but film caps bring the sound to another level!
Depends on the Quality. Often they are worse. To much focus from upper midrange to treble. I always use KP and not MKP.
Ok, I never intended to start a neverending debate on caps...
I just wanted to give people who wish to try installing film caps a useful picture diagram. That's all.
Ok finished "pioneer kit" this evening. Voltages check at first then, all decline.
I checked all solder connections, then passive components and then active components.
Ah Ha moment. I didn't check the bag of Q1 and Q2 to make sure that I had same four transistors in each. Just soldered them in place. My bad.
Q1 bag = 4- J113 KH33
Q2 bag = 3- J113 KH43 and 1-KH33
I suspect this is why I have nothing.
Please help me Nelson!!
Regards
David
I checked all solder connections, then passive components and then active components.
Ah Ha moment. I didn't check the bag of Q1 and Q2 to make sure that I had same four transistors in each. Just soldered them in place. My bad.
Q1 bag = 4- J113 KH33
Q2 bag = 3- J113 KH43 and 1-KH33
I suspect this is why I have nothing.
Please help me Nelson!!
Regards
David
I think those are the date codes...
Your transistors appear to be 7.3 in both bags, so you should be able to mix/match with no detriment.
Can you post a couple well-lit, in-focus photos of your PCB? If you can show the back that would be helpful as well.
Your transistors appear to be 7.3 in both bags, so you should be able to mix/match with no detriment.
Can you post a couple well-lit, in-focus photos of your PCB? If you can show the back that would be helpful as well.
You cannot adjust t8 with the pot? Perhaps your pots were not set equally when you started it up.
This is a very interesting preamp. I’ve spent the day listening to it...my voltages were spot on per the guide.
Iam using a Meanwell smps, Panasonic fm (2700uf) in the psu and wima 6.8uf polyester bypassed with .1 uf polyproplyne under the board. Pots are $1 alphas.
The sound? It’s different from what Iam used to for sure. My current preamp is a current mirror design of Juma’s. It’s very good and has a beefy super reg psu. I also have the salas dcg3. Also I have built the ba-3. All of these have good psu and stepped attenuators.
I expected the Korg to sound soft and lack detail. It does not. I expected it to be bloated and slower. It’s not. I expected it to be noisier...it’s not. I expected it to be overwhelmed by complex music. It was not.
What it does do different than the above preamps is layer front to back. Sometimes it sounds too forward, sometimes too recessed. It’s really picking up cues from the recording and varies from album to album.
Bass is admittedly a little looser than the SS preamps. Not much... just a little.
I thought it would sound “dark” but actually I find it a bit bright? Like a little upper midrange emphasis? I actually lowered my to tonarm 1mm to compensate.
Treble is a little grainy. Maybe it’s the polyester caps...just seems a little artificial. Especially on cymbals.
But overall it sounds more “alive” than my other preamps. I little more exciting...I was not expecting this. And the sense of depth information is really neat. There is a sense of reverb or wetness that my SS smps don’t have although it’s subtle.
My build is really more of a prototype than anything. Better psu, pots and caps would surely help. The soundstage of this thing is pretty addicting though. The closest preamp I have now to it is Juma’s current mirror. It sounds similar, the soundstage is not as 3d but it has better control. It’s a trade off...
Lastly, I have experimented with H2 games in SS preamps with the Ba-3 and Juma’s preamp...the effect is similar but not the same. With the SS preamps you ad H2 and gain depth at the expense of width and dynamics. With the Korg it seems like the added H2 has fewer drawbacks. The dynamics are still there. The leading edges are still crisp.
Really interesting piece this is.
