[DavidK35]

Anyone tried the 6K6G/GT? Dirt cheap, especially the G. Same pinout & only 0.4 heater amp draw (similar to the 6V6).

 

[CZ4A]

Anyone tried the 6K6G/GT? Dirt cheap, especially the G. Same pinout & only 0.4 heater amp draw (similar to the 6V6).

I've tried a couple of different pairs 6K6s a while ago (Sylvania 6K6G and GE 6K6GT) and I don't remember being that impressed with them. I can give 'em another listen compared to my NOS Tung-Sol 6V6GTs tonight or tomorrow.

I think the best budget NOS power tube for the APPJ is the 6W6GT. They're cheap, plentiful, linear, and pretty darn nice-sounding. They do have a whopping 1.2A power draw but that's just within spec.

 

[DavidK35]

That's good to know, thanks for that, I will order them next week. Please let me know how your listening tests go.

 

[CZ4A]

I I had a quick listing test between the vintage black glass Tung-Sol 6V6GT and the Sylvania 6K6G. The headphones were HE-500 and the preamp tube was a Raytheon 12DT7. The coupling caps are WIMA MKP4 0.47uf.

I'm no good at describing sound but I found the 6K6G tubes to be too smooth for my liking. The bass lacked punch and overall I felt they weren't as lively or detailed as the 6V6GT tubes.

 

[Maxx134]

Anyone tried the 6K6G/GT?

Yep they cheap and not bad, but they started to spark with demanding passages so I pulled them out quick.

Average sound no where as good as a 6V6 type..

 

[Maxx134]

My top most transparent combo is:

Driver tube:
12SL7 SILVER ROUND PLATE
No matter the brand they same construction used with various brand.

Get the adapter as it is really worth upgrading to the larger bottle 12SL7 type tube.

Power tubes:
the 6F6, specifically the Russian 6Ф6С / 6F6C Cobra...
(Thanks to member "Kryl007" for that recommendation.)
Best transparency of 6F6 type and cheaper too..

 

[Hippocamp]

Picked up this amp used. First impressions are very positive! Black background. Nice soundstage. Excellent clarity.

It came with a set of extra tubes (a pair of JJs and a Mullard).

My plan is to use this mostly with my Beyer DT1990 pros, which are fantastic (great bass, soundstage, and awesome detail retrieval) but just a little dry in the treble.

Any suggestions for a tube combination that would bring some liquidity to the highs?

 

[baronbeehive]

Picked up this amp used. First impressions are very positive! Black background. Nice soundstage. Excellent clarity.

It came with a set of extra tubes (a pair of JJs and a Mullard).

My plan is to use this mostly with my Beyer DT1990 pros, which are fantastic (great bass, soundstage, and awesome detail retrieval) but just a little dry in the treble.

Any suggestions for a tube combination that would bring some liquidity to the highs?

I can only comment on the driver tube, as I have the other, speaker APPJ which has EL84 power tubes, but for liquid highs the Tungsol 12SL7 is amazing as I said a few posts ago. You would need a 12Ax7 to 12SL7 adapter though. Alternatively you could try the 12AX7 substitute, the TS 5751 which is slightly earthier and more live sounding but just as liquid in the trebles, and fits straight in. Also it's easier to get hold of. The thing with the TS's is that they are very liquid sounding but some people don't like them because of their sweetness, others love them however! The other thing is that for some the treble is slightly rolled off, I don't find this but then I don't like very sharp sounding treble.

Also any silver plate 12SL7 as Maxx134 said a few posts ago would be good, such as a GE.

Incidently I find the JJ ECC83S driver tube to be very smooth sounding as well for a new issue tube, great soundstage and very lively bass.

 

[Maxx134]

Gemtune Amp Part 1

Got my amp last week & been burning in tubes & auditioning. Still waiting for adaaptor & 12SL7/12SN7 tubes...

seemed to have overlooked your post..
Very nice!
Yes best driver tubes are 12SL7

I think I am the first in this thread to use the 6BG6 G series tubes that have the external wire & cap with suitable adaptor....

Wow big monster tubes!!
Haha nice!

So far I think this is the best sounding head amp I have tied so far (#6) so cannot wait to roll some other tubes. .

Wow you tried 6 other amps, care to say which?
This amp modded is pretty high up in level so understandable .

Coming are the 6SN7 & 6SL7 drivers + 6AG6G/EL33 power tubes.

DO NOT USE 6SN7 & 6SL7 tubes for driver.!!!
They require adapter which gets hot due to cheap resistor inside...

Use the 12V versions:
12SL7 & 12SN7.

I ordered my amp without tubes for $159.00 + $30 fedex 5 day.

Wow dirt cheap!

Time will tell if the 6BG6 proves better or not than the 6AG6G types & I may also try the 6L6G types but they are a bit pricey.

Do not bother with the 6L6 type.
Since the bias is not optimal for them,
they end sounding a bitt vague and distant, and not as vivid as the 6F6 type.

Intimidating power tubes!
Ha

 

[DavidK35]

To answer your questions:

1) post was a mistake should have read 12SL/N7 not 6SL/N7

2) 6 amps in total, the other 5 were:

INDEED 12v tube type (open frame) with 6211A tube. Failed after 2 years. Ran very hot too.
CTH (compact tube hybrid) various tubes. Too dry & sibilant for me.
CIVILIAN 6N2 + FU32 (6AX7 + 32 NOS tubes). Ran extremely hot. OK but heat was issue for me
LITTLE BEAR P8 (1 x 6AS7G + 2 x 6SN7 NOS with adaptors). Very good with the 6SN7's (new issue Tung Sol).
BREEZE E200 (2 x 6C8G + adaptors, 1 x 7F7 + adaptor or 6211A, all NOS.) Still have it but definitely not as good as
the Gemtune even though the transformers are much bigger, + size & weight much more. The circuit design must be
superior IMO. The LB P8 ranks #2 but is bested by the Gemtune.

 

[Maxx134]

Wait untill you do the upgrades to your unit...

 

[Hippocamp]

Yes best driver tubes are 12SL7

Will 12SN7 tubes perform similarly? Seem to be a lot more of that type available than 12SL7.

 

[Maxx134]

No,
the original circuit cost for an 12 ax7 output type ,
and so you need an 12SL7 type for the similar mu gain.
you don't want a tube that sounds duller or not as Lively

 

[baronbeehive]

Wait untill you do the upgrades to your unit...

He he.... why would anyone not want to do that.....!!
Easy to do on this unit, only problem the pads are tiny and easily disturbed, these are the repairs I had to make:

Will 12SN7 tubes perform similarly? Seem to be a lot more of that type available than 12SL7.

Did you manage to pick up any TS5751's, it's a matter of luck if you can find any 12SL7's atm! I have the 5751's in mine and don't really need anything else.

 

[Maxx134]

5751 type is prob the best 9pin i ever tried...
Edit or at least the most resolving.
There is always a stand out tube in every type like the 180cc and e80cc types which had a bit more Soundstage at trade off of liveiness..

For a driver stage, better to have the most resolving tube, like the resolving 5751.
Best for me yet was the 12SL7 8pin with adapter.

You can gain back any Soundstage lost with power tubes choice anyways.
The 6L6 on this amp does it with largest Soundstage while sounding refined,
But at a trade off of sounding more laid back.

The 6v6 are most balanced ,
but for me the 6f6 was most resolving.