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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 267

post #3991 of 7247

Here is small list of octal tubes that i could recommend to use with little dot.

 

Driver octals:

6SL7GT = VT-229     Classic type
= CV1985
6SL7W                    Sylvania
6SL7WGT                Rugged version with smaller parts
6SL7WA                  Military version
6SL7GTB                 Lower base
6SU7GTY                Better quality and balance? Tung-Sol
6SU7WGT = 6188     Ruggedized and bantam construction
ECC35                    European version with 0.4A heater
6N9S (6H9C)           Russian
6N9M (6H9M)          Russian mini version
1579                      Russian, better quality?
6N9P                     Chinese
6N9P-T                  Chinese, better quality?
6113                     Low microphonic?
5691                     Better quality? 0.6A heater

 

Power octals:

6SN7GT = VT-231     Classic
6SN7GTA                 More power?
6SN7GTB                 Like -A but with faster heating
6SN7GTY = CV1988   Better quality?
6SN7WGTA              Ruggedized and bantam construction
6SN7W                   Sylvania
5692                      Better quality?
6N8S (6H8C)           Russian
1578                      Russian, better quality?
6N8P                     Chinese
6N8P-T                  Chinese, better quality?

post #3992 of 7247
Quote:
Originally Posted by Nic Rhodes View Post
 

Tung Sol 6SU7GTY is a wonderful tube but look out for the 6188 also. You can also find 6188 by Sylvania / PhilipsECG at much better prices.

 

6SL7GT: 6SL7GT, 5691, CV1985, 6113, 6188, ECC35, CV569 [VT 229]

 

6SN7GT: 6SN7GT, 6SN7GTB, 6SN7WGT, 6SN7WGTA, 6SN7WGTY, 5692, 6180, CV1988, CV3627, B65, ECC33, CV2821, ECC32, CV181, QA2408 [VT 231]

 

The are a few other close variants but the above should get some searching effectively.

ECC33 Gain 35, 0.4A heater. Somewhere between 6SL7GT and 6SN7GT.
ECC32 Gain 32, 0.95A heater. Perhaps works as powertube?

post #3993 of 7247

Here is visible 6N8S differences from different decades. Older has also taller base. Right one can't be made in Holland...

700

 

I have 6 Russian 6N9S's and i could be hearing things, but somehow this "RADIO lampa" sounds better than the others. So if someone is going to buy cheap 6N9S i recommend to look for this. Mine have date code 12-86. Still quite not good as Tung-Sol 6SU7GTY's, but cheaper.

700

 

This ebay auction is very interesting. Pair of better russian 1579. I'm trying not to bid. 

http://www.ebay.co.uk/itm/RUSSIAN-TUBES-1579-6SL7-6N9S-DOUBLE-TRIODE-TUBES-Lot-of-2-NEW-in-BOX-/151162326986

post #3994 of 7247

I just receieved this 80's NOVOSIBIRSK 6N6P-i GOLD GRID TUBES and it make my MK III very very hot is this normal? The stock tube i know it make the body of MK III warn to the touch but the 6N6P-i it make it very hot.

post #3995 of 7247

I had one non-working trigon 6SL7GT and its base was good for doing adapter for 12AX7 tubes.

700

With this i could try to compare 6SN7GT and 6N6P-IR powertubes one day.

post #3996 of 7247

I just found a bit of time to listen to a full album or two with one of my two new Amperex 6922.

 

The first one I had given a good listen to was an Amperex "USN-CEP" 6922 made in 64-52, this one is an Amperex "USN" 6922 made 62-16; same exact construction,but glass may be a little less darkened (less of the "sun glasses effect").

 

Oddly enough, I could swear that these two tubes don't sound exactly the same. They definitely share very similar traits, but the '62 tube seems more holographic with extreme micro-detail retrieval, and a bit more warmth and body, whereas the '64 seems very extended with hard-hitting punchy bass. I think I prefer the '62 tube actually (it really sounds like the description of an Amp'ex PQ 6922 made on Joe's tube lore actually, whereas the '64 tube sounded a little drier, like Joe's impressions of the Amp'ex USN 6922...).

 

Hopefully, I'll get a chance to know if my mind is just playing tricks on me when I test the third tube, an Amperex "USN-CEP" made 65-08. If that tube also sounds different from the '62 and similar to the '64 (8 weeks apart), then I'll know that I was right. If it sounds similar to the '62 or different from both other tubes, then I'll start worrying lol.

 

Listening with the '62 tube, it definitely has that "spooky feeling that you're in the music room the artist tried to design and record"; the '64 tubes gave me the "ultra detail everywhere in the room effect", but not the spooky real feeling.

 

Edit: I just realized that '62 version of the tube sells for $140 for a single lol. No wonder it sounds good...

Edit 2: $170 on "premium" tube resellers... Holy Schiit...


Edited by Audiofanboy - 11/16/13 at 9:10am
post #3997 of 7247

Guys someone should do a complete recap of all the current best tubes.If not for certain FM I would have got lost in this thread.Finally on my way to order 6hm5 and 6n6p-ir and hopefully be happy for a while.

  Also can anyone tell me if op-amp rolling affects sound ? Also is the op-amp easily swappable ? I read somewhere in this thread that LME49990 and/or OPA627AP are good options.

 

Let me know.

post #3998 of 7247

Here is little list of tubes and variants, that should work now with boxed little dot. List is with heater currents and amplification factors.

 

6V tube types
 
ECC88 6DJ8 6N23P CV5358 M3624        0.35A 33x
E88CC 6922 CCa CV2492 CV2493 9622  0.30A 33x
E188CC 7308 CV4108                         0.35A 33x
E288CC 8223                                    0.47A 25X
ECC85 6AQ8 B719 6L12                      0.44A 57X
ECC86 6GM8 6N27P                           0.30A 14X
ECC189 6ES8                                   0.36A 31X
ECC804 6GA8 6/30L2                         0.30A 18X
ECC812                                          0.44A 50X
ECC865                                          0.44A 58X
ECC180 6BZ7 6BQ7 6BS8 6T27           0.40A 36X
6N2P 6CC41                                    0.34A 100X
6BK7                                              0.45A 40X
6BC8 6BZ8                                      0.40A 35X
PCC88 7DJ8                                     0.30A 33X
6AU7                                              0.30A 20X
6AX7                                              0.30A 100X
6BX8                                              0.40A 25X
6CH7                                              0.40A 36X
6DT8                                              0.30A 60X
 
 
 
12V tube types
 
ECC83 12AX7 B339 95-127-01 6L13 CM1        0.30A 100X
ECC82 12AU7 B329 95-126-01 CC82E CV491  0.30A 17X
ECC81 12AT7 B152 CC81E CV455                 0.30A 60X
E81CC 12AT7WA CV6091 6201                     0.30A 60X
E82CC 6189 M8136 6189W                         0.30A 17X
E83CC 12AX7WA 6057                              0.30A 100X
E180CC CV8431 7062                               0.40A 50X
E181CC                                                  0.40A 32X
ECC186 12AU7WA 7316                              0.30A 17X
ECC802S                                                 0.30A 17X
5751 GL5751 CK5751 CV4017                      0.35A 70X
5814A CK5814-A                                      0.35A 17X
5963 CV3900                                           0.30A 21X
5965 6829                                               0.45A 47X
6679                                                      0.30A 60x
7025                                                      0.30A 100X
12AD7                                                   0.45A 100X
12DF7                                                   0.30A 100X
6680                                                     0.30A 20X
6211                                                     0.30A 27X
12AZ7                                                   0.45A 60X
12AD7                                                   0.45A 100X
12AV7                                                   0.45A 40X
12AY7 6N4P                                           0.30A 40X
12DM7                                                   0.26A 100X
12DF7                                                   0.30A 100X
12DT7                                                   0.30A 100X
12U7                                                     0.30A 20X
6072                                                     0.35A 44X
6681                                                     0.30A 100X

Edited by Artsi - 10/21/13 at 1:57pm

                                                                                                                                                                                                                                                                                                                                            

Here is small list of octal tubes that i could recommend to use with little dot.

 

Driver octals:

6SL7GT = VT-229     Classic type
= CV1985
6SL7W                    Sylvania
6SL7WGT                Rugged version with smaller parts
6SL7WA                  Military version
6SL7GTB                 Lower base
6SU7GTY                Better quality and balance? Tung-Sol
6SU7WGT = 6188     Ruggedized and bantam construction
ECC35                    European version with 0.4A heater
6N9S (6H9C)           Russian
6N9M (6H9M)          Russian mini version
1579                      Russian, better quality?
6N9P                     Chinese
6N9P-T                  Chinese, better quality?
6113                     Low microphonic?
5691                     Better quality? 0.6A heater

 

Power octals:

6SN7GT = VT-231     Classic
6SN7GTA                 More power?
6SN7GTB                 Like -A but with faster heating
6SN7GTY = CV1988   Better quality?
6SN7WGTA              Ruggedized and bantam construction
6SN7W                   Sylvania
5692                      Better quality?
6N8S (6H8C)           Russian
1578                      Russian, better quality?
6N8P                     Chinese
6N8P-T                  Chinese, better quality?

 


Edited by MIKELAP - 11/16/13 at 4:57pm
post #3999 of 7247
post #4000 of 7247
Quote:
Originally Posted by gunnerwholelife View Post
 

Guys someone should do a complete recap of all the current best tubes.If not for certain FM I would have got lost in this thread.Finally on my way to order 6hm5 and 6n6p-ir and hopefully be happy for a while.

  Also can anyone tell me if op-amp rolling affects sound ? Also is the op-amp easily swappable ? I read somewhere in this thread that LME49990 and/or OPA627AP are good options.

 

Let me know.

What is your Little Dot model? You can't do both, swapping op-amp and use 6N6P-IR's?

post #4001 of 7247

Hi Artsi,

 

Since each channel in the LD MKIII is completely independent, I tried in the past to compare different tubes in each channel, as you suggest (comparing the octal 6SN7GT to the 6N6P-IR tubes).

 

I gave up because IMHO, even though the channels are separate, there is a synergistic effect that takes place, and you don't get a true picture. However, if you could wire each channel separately to play both channels in your headphones or speakers, you could take a very good monophonic recording and compare each channel by switching from side to side.

 

I could not figure out how to do this, but maybe you can.

 

Playing two different tubes and turning the balance control to this side or that side did not work for me; having two tubes that are the same and switching pairs (which entails waiting for the amp to cool down) worked to differentiate different sound.

post #4002 of 7247
Quote:
Originally Posted by gunnerwholelife View Post
 

Guys someone should do a complete recap of all the current best tubes.If not for certain FM I would have got lost in this thread.Finally on my way to order 6hm5 and 6n6p-ir and hopefully be happy for a while.

  Also can anyone tell me if op-amp rolling affects sound ? Also is the op-amp easily swappable ? I read somewhere in this thread that LME49990 and/or OPA627AP are good options.

 

As others have noted, if you have power tubes, then you don't have an op-amp. The Little Dot 1+ , which I have, is a hybrid, with driver tubes and an op-amp, and therefore, rolling op-amps is possible.

 

Regarding the best driver tubes... to get you started.... 

 

Running two single driver tubes, I would recommend pairs of RCA 6DT6 and 6HM5 (which you have apparently already ordered).

Running one double triode, I would recommend an Amperex Orange Globe 6DJ8 from the late 1960s (with a halo getter), and a Voshkod 6N23P from the late 1970s.

post #4003 of 7247

Want to order an adapter 6SL7 TO 12AX7 like this one here but i noticed at bottom of page its marked 6.3 volts shouldnt it be marked 12v since its the 9pin 12ax7 thats going into my setup                  http://www.ebay.com/itm/2ps-convert-tube-socket-12AX7-12AU7-to-6SL7-6SN7-9-pin-to-8-pin-/281034346185?

Processed By eBay with ImageMagick, z1.1.0. ||B2

post #4004 of 7247
Quote:
Originally Posted by MIKELAP View Post
 

Want to order an adapter 6SL7 TO 12AX7 like this one here but i noticed at bottom of page its marked 6.3 volts shouldnt it be marked 12v since its the 9pin 12ax7 thats going into my setup                  http://www.ebay.com/itm/2ps-convert-tube-socket-12AX7-12AU7-to-6SL7-6SN7-9-pin-to-8-pin-/281034346185?

Processed By eBay with ImageMagick, z1.1.0. ||B2

 

This should work fine. I bought mine from another vendor:

 

http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

However, both look the same to me.

 

And 6 volts is correct. Fortunately, the 12AX7 can be used with either 12 volt or 6 volt heaters. The Little Dot heater supply voltage is 6 volts, so we wire the 9-pin socket (by using pin 9) to run the 12AX7 on 6 volts. And since the 6SL7 is also a 6 volt tube, it works flawlessly.

post #4005 of 7247
Quote:
Originally Posted by gibosi View Post
 

 

This should work fine. I bought mine from another vendor:

 

http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

However, both look the same to me.

 

And 6 volts is correct. Fortunately, the 12AX7 can be used with either 12 volt or 6 volt heaters. The Little Dot heater supply voltage is 6 volts, so we wire the 9-pin socket (by using pin 9) to run the 12AX7 on 6 volts. And since the 6SL7 is also a 6 volt tube, it works flawlessly.

Thanks for the infos gibosi  if only my sockets could get here would start working on adaptors things move fast these days trying to keep up

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