[mamaloney]

So, I want to get a LD mk1+ and throw a pair of Voshkod 6ZH1P-EV tubes and an opa2107 op amp into it, how exactly do I swap these parts out? Is there any special equipment that I need or tweaking that I have to do, or is it pretty straightforward? I'm new to this kind of stuff.

 

[cassper]

Quote:

Tried to do a little research on the deciphering of the OTK symbol and the various numbers in the rhombus following the OTK letters.
Basically, OTK is a Russian abbreviation for Quality Control. It is a symbol that is used on a number of products, and it is not specific to military use only. Sometimes the OTK letters are followed by a number, i.e. OTK 23. This simply means Quality Control, inspected by inspector 23.
 
The numbers within the rhombus could be 1,3, 5, 7 and 9. The meaning of these numbers is as follows (from a Russian seller on EBay):
[size=10pt]1 - usual OTK
3 - usual + climate test
5 - military
7 - military + climate test
9 - a special series[/size]
 
Some of my Russian tubes have the OTK symbols printed on them and some not. Those that do not have them probably come from bulk packages that have the  OTK symbols  printed on the large box they came packaged in. (So far I have seen the numbers 1, 3 and 5 on my tubes.)
 
My source claims that for audio use the different rhombus numbers do not matter. I would venture to guess that category 5 and 7 may be more rugged, perhaps corresponding to the W (6AK5W) in the US nomenclature, which indicates a more rugged construction for military use.

Two days ago I received 6J1P-EV with a rhombus and nr 6. They have OTK7, date code 9006. No factory logo - and they have grooves.

 

[mordy]

Don't know what the number 6 means in the rhombus - why don't you ask the seller if he knows? This kind of information is hard to find.

 

[Napkin]

Thanks for this awsome Guide! I'm also wondering like mamaloney how I'm supposed to go about when changing the tubes & OP-amp!

 

[Tribbs]

Here is a link to some Russian tube info http://www.arrakis.es/~igapop/russianotes.htm
 
I have a Voshkod 6Ж1П-ЕВ tube with the number "47" inside the rhombus, OTK1, date(?) 07-87.
I have two others with the number "10" inside the rhombus, both OTK1, both date(?) 03-88.

 

[Melvins]

Just received some Voshkod 6ZH1P-EV EF95's from a fellow headier and so far I adore them! Spot on description in OP's post. So smooth, very good for metal/rock and a perfect combination with the Grado's.

 

[infinity650]

Hello,
 
please forgive my poor language - german guy.
 
I'm reading especially this thread for a few weeks and bought some tubes for my MK IV SE. I was lucky and got the 6H30 DR "Supertubes" right from the start. Long story, but I didn't pay the bunch of money for them.
 
Now I want to list all of my tubes and post my impressions so far.
 
Powertubes:

2x 6H30-DR  -> nothing to complain about, much better than stock tubes but if it was my money I wouldn't buy them again - too expensive
2x 6H30PI Gold-Pin  -> nothing to complan about either, in my ears pretty much the same as the "super tubes". Really recommend buying them, worth the money, acceptable price in my eyes


Drivertubes (EF95):

2x Voskhod 6ZH1P-EV    -> great detail and treble, nice bass. can sound harsh with bad recordings - but who listens to bad recordings
2x Mullard M8100/CV4010         -> lot of bass, warm and gentle. to me great for singer/songwriter, relaxed sound, less detailed, but great  
2x RCA 5654 (Black Plate)     -> on their way to me
2x GE JAN5654W EF95         -> on their way

Drivertubes (EF92):

looking out hardly for some Mullard CV4015 for a nice price! If you want to offer them to me you're welcome! I owned them but sold them with my former MK III.

Drivertubes (EF91):

2x Mullard CV 4014    -> on their way
 
 
Also looking for: (offers welcome)
 
Sylvania GB 5654 EF95
Mullard CV4015 EF92
Voskhod 6J1P EF95
Tung-Sol 6AK5 EF 95
United Electron EF92   
Mullard CV131/6CQ6
 
 
 
I previously owned the MK III stock tubes (really nothing special about them) and some Valvo EF92. These were pretty dark and undetailed. Maybe cool with some Bob Marley kind of music, but no good to me.
 
That's it, let me know what you guys think and I wolud be happy to get feedback.
 
 
Greetings,
 
Nik

 

[rogan]

Hope this is the right thread
 
My MK II is about to arrive, i use grado sr-125i's (32ohm i think) what gain setting shud it be on..?

 

[rosgr63]

Congratulations, enjoy it!
I would start from the lowest gain.

 

[Melvins]

Quote:

Hope this is the right thread
 
My MK II is about to arrive, i use grado sr-125i's (32ohm i think) what gain setting shud it be on..?

3.5. My little dot came with this gain setting already set up.

 

[Melvins]

but just to be sure I'd open that bad boy up and see what's up, the booklet that comes with the amp is pretty straight forward. 

 

[rcw9]

Does anyone know if the Power Tubes were ever reviewed?  I saw one posting suggesting the 6H30P-DR's but way to expensive!

 

[mordy]

We are all waiting for the power tube review from Department of Alchemy (first post on this thread).  It's over half a year already, and I would really like to read the reviews about the power tubes!
DOA - are you there? Could you at least give us a progress report?

 

[infinity650]

Hello,
 
I own them. They are f* great, but way too expensive! They give just a little bit more control, a little bit more authority, but just buy the gold pins, they're nearly  as good and much much cheaper. I own them both, so I have a real comparison.

 

[rcw9]

Hi Infinity,
 
I assume you're talking about the 6H30P-DR's?  Gold Pins.  Do you have a model number and source.  
 
I'm new to the tubes and find it really confusing figuring out what matches to what tube etc.
 
 Any guidance is most appreciated!
 
Thanks!