LOMO KINAP YM-39 (1 channel YP-27) tube PIN OUT? SCHEMATIC?

[peeping tom]

Hi guys,
I just ordered one of these  vintage russian tube pre's and I'm looking to find some information for it....
Does anyone have had any experience with this particular model. Any information would be aprichiated!
The biggest question for me are the pin out wiring diagram with the right voltage ratings and how to use the output of this thing....did I need to put any transformer or can I use it the way it is?

Thank you in advance guys! I hope someone can help me...

Mihail

 

[ungifted]

Hi Mihail, where are you from?
Here is discussion at russian guitar community
http://forum.gtlab.net/cgi-bin/yabb2/YaBB.pl?num=1364891711/0
This pre is from "Звук 4-25М", 1pc - 6zh32p and 6n3p tubes. Schema attached. Please look through thread - some more docs available (trafo info etc)
There was full docs scan, but not available at the moment. You can ask there (your name is russian)

 

[ruffrecords]

Is L1 really 25 micro Henries?

Cheers

Ian

 

[peeping tom]

Hi Mihail, where are you from?
Here is discussion at russian guitar community
http://forum.gtlab.net/cgi-bin/yabb2/YaBB.pl?num=1364891711/0
This pre is from "Звук 4-25М", 1pc - 6zh32p and 6n3p tubes. Schema attached. Please look through thread - some more docs available (trafo info etc)
There was full docs scan, but not available at the moment. You can ask there (your name is russian)

Hey,
I'm so happy that someone joins this thema! Thanks you!
I'm from Bulgaria and unfortunately I'm not familiar with the russian language...so i'll try to read the thread at least for some technical factology.(the alphabet is the same)
The biggest mystery for me is the output of this preamp. Does it needs transformer or already has one? If it does need one then what specifications?
Thank you very much for the reply!
Cheers!

 

[emrr]

Interesting circuit.

 

[shabtek]

Yes quite interesting.
Should not require output transformer---2:1 to 5:1  step down  if you want isolation and balance.
I'd like an explanation of the feedback / bias etc related to the input transformer

 

[peeping tom]

Yes quite interesting.
Should not require output transformer---2:1 to 5:1  step down  if you want isolation and balance.
I'd like an explanation of the feedback / bias etc related to the input transformer

Is there a way to bring the upper frequency responce above 14 000 Hz? 16 000 would be more usable for some purposes...

 

[shabtek]

Is there a way to bring the upper frequency responce above 14 000 Hz? 16 000 would be more usable for some purposes...

I can't hear that high, but what leads you to believe hf response is limited;

 

[peeping tom]

Is there a way to bring the upper frequency responce above 14 000 Hz? 16 000 would be more usable for some purposes...

I can't hear that high, but what leads you to believe hf response is limited;

the frequency responce is rated for 40HZ- 14000Hz. by the specifications

 

[emrr]

Rated to what deviation?  This is really not a problem in practice.  There are lot's of legacy pieces rated 50-10K that studios use all the time with no complaints.    Virtually nothing cuts off terribly hard at the rating edge, 16kHz is certain to be present. 

 

[peeping tom]

Rated to what deviation?  This is really not a problem in practice.  There are lot's of legacy pieces rated 50-10K that studios use all the time with no complaints.    Virtually nothing cuts off terribly hard at the rating edge, 16kHz is certain to be present.

Actually I don't know what is the standard for these preamps. For some other pre's I've seen the deviation is about 3 db so I've got your point. I have Neumann CVM563 with M7 wich is rated up to 16 000Hz, but there's nothing actually missing when used on voices so....

 

[peeping tom]

Now I'm looking to find  a good power supply schematic for this one! I decided to build it my self, but I'n not sure witch schematic to use.I will need +250VDC for B+ and 6,3V (AC?) for the heaters. I've found one old power transformer rated for 230 primary and 250 and 6,3 secondary and I ques  it will do the job? Now I'm  wondering  if I can use AC for the heaters or I must use DC ???Any suggestions? 

 

[korneev]

Schematic.

 

[duantro]

I'm racking up a pair of up35 (27) and am going to use EA2503 output transformers. These things look  pretty interesting.

 

[peeping tom]

Hey guys! I still have mine ( racked years ago ) and works very nice with my dynamic microphones, but when I tried my Neumann U87 condenser mic (with the original phantom power) it doesn't work. Of course the mic works in my other preamps, but I wanted to hear it in this wonderful tube preamp...Does anyone has some idea what can be wrong? I wired the input transformer two leads to the 2 and 3 of the XLR' input and the ground I connected to pin 1 of the XLR as for balanced input. Is that correct?It works perfectly with my dynamic mics, but for some reason doesn't take the condenser mic ( after the 48 phantom power of course that I'm using for my other pre's and works perfect)
I will appreciate any help!
Regards!

 

[TimG]

Hi Tom, what did you do for your power supply?

 

[peeping tom]

Hi Tom, what did you do for your power supply?

Hi!
I made it myself from old hi fi tube amp power transformer in a computer power supply box. It works flowless. It was long time ago actually and I haven't used it much since then, but now I started comparing it to my other pre's ( neve 1073 based preamps) and I really like what it does . It's thickering the vocals very nice and adding nice character. Saddly I can't use with with my Neumann U87( with separate phantom power) for some reason. That's why I resorected this topic if some of you guys have some clue what can it be

 

[opacheco]

peeping tom​

Do you have the schematic of your preamp?

Thanks
opacheco

 

[loylo]

@peeping tom​

I don't know if you're still hanging on groupdiy.
The reason why you have a problem with phantom power is because of the input transformer. As you can see on the schematic, there is a middle point connected to ground so if you apply 48V to the input transformer, the reference for all the preamp is no longer 0V but 24V.

 

[peeping tom]

@peeping tom​

I don't know if you're still hanging on groupdiy.
The reason why you have a problem with phantom power is because of the input transformer. As you can see on the schematic, there is a middle point connected to ground so if you apply 48V to the input transformer, the reference for all the preamp is no longer 0V but 24V.

Thank you so much! I finally made it work with my condenser mic. I unattached the center tab from the input transformer and now it works with 48V Phantom Power. Thank you!