Little Dot Tube Amps: Vacuum Tube Rolling Guide
Mar 25, 2014 at 2:21 PM Post #5,581 of 13,438
Hi mab1376,
 
Seems hard to find C3g tubes but here I came across an adapter:
 
http://www.ebay.com/itm/1x-C3G-to-6AK5-8Pin-to-7Pin-Vacuum-Tube-socket-Convert-Socket-Adapter-/301131714830?pt=Vintage_Electronics_R2&hash=item461cd9510e
 
Price seems steep - $35 for one.
 
Meanwhile I am listening to the combination of RCA 6SN7GT power tubes and a GE 6BX7GT as driver. Really very nice. GT means Grand Touring if my amp was a car. Now GT just means Glass Tube. 
 
I'm afraid that my beloved 6N6P-IR tubes will be relegated to the the dust bin......At least they have good company; some 300+ sibling tubes.
 
Here is some (blah blah) listening impressions:
 
Super wide, airy and open, extremely spacious 3D holographic sound stage, super detail everywhere without being etched but very musical instead, very powerful, fat and detailed bass that goes really low, pinpoint imaging and instrument separation, sweet midrange etc.
 
On the con side: A little bright but not sibilant, could be quicker with more slam. It is also interesting to note that this tube combination needs to warm up some 20 minutes to sound its best.
 
Nah, strike the blah - this is real, this is cracking!
 
British Slang: Cracking - If something is cracking, it means it is the best. Usually said without pronouncing the last "G".  Thanks, Nic.
 
Mar 25, 2014 at 2:32 PM Post #5,582 of 13,438
  So...I know I am asking a much repeated question; can one run a 6CY7 in a LD 1?

 
First, you should know that while the 6CY7 is a double triode, the triodes are deliberately dissimilar. One triode was intended to operate as a vertical-deflection oscillator and the other, an amplifier, combined in one tube, for use in television receivers. Not a good candidate for use in our LDs, IMO....
 
Mar 25, 2014 at 2:37 PM Post #5,583 of 13,438
Thanks HUGELY!
That's why one asks questions before blowing up one's gear.
cool.gif

I always appreciate how I will receive nice, pertinent answers to questions here on HeadFi.
 
smile.gif
 
 
Mar 25, 2014 at 2:50 PM Post #5,585 of 13,438
A heads-up for those of you buying 6SN7s...
 
To the best of my knowledge, Mullard never made a 6SN7GT. Therefore, if you see a Mullard 6SN7GT, it was manufactured elsewhere, and simply relabeled. Furthermore, these tubes are typically of Russian origin.
 
Note this listing:
 
http://www.ebay.com/itm/Mullard-6SN7GT-Made-In-England-Grey-Plates-Tube-B-K-Tested-/191114223492?pt=Vintage_Electronics_R2&hash=item2c7f4b9f84
 
And take a good look at the getter....  That "flying saucer" getter is a dead giveaway that these are of Russian origin and definitely were not manufactured by Mullard or any other Philips subsidiary. And if this tube really was manufactured in England, the equipment used in its manufacture was of Russian origin.
 
Mar 25, 2014 at 3:06 PM Post #5,586 of 13,438
I simply LOVE finding the Gurus of HeadFi.org.
 
You guys are AWESOME in your knowledge of the details that make superior gear...SUPERIOR.
 
I don't know how many tube I.D. charts I've had to run through to be sure about my purchases being the genuine item.
BEWARE of inadequate photo-representation of what you are purchasing!
I often ask for close-ups of specific parts of an item just so that I know....
if they won't comply, I am immediately suspicious.
 
Thanks so MUCH for making HeadFi a super place!
bigsmile_face.gif
 
 
Mar 25, 2014 at 3:45 PM Post #5,587 of 13,438
  Hi mab1376,
 
Seems hard to find C3g tubes but here I came across an adapter:
 
http://www.ebay.com/itm/1x-C3G-to-6AK5-8Pin-to-7Pin-Vacuum-Tube-socket-Convert-Socket-Adapter-/301131714830?pt=Vintage_Electronics_R2&hash=item461cd9510e
 
Price seems steep - $35 for one.
 
Meanwhile I am listening to the combination of RCA 6SN7GT power tubes and a GE 6BX7GT as driver. Really very nice. GT means Grand Touring if my amp was a car. Now GT just means Glass Tube. 
 
I'm afraid that my beloved 6N6P-IR tubes will be relegated to the the dust bin......At least they have good company; some 300+ sibling tubes.
 
Here is some (blah blah) listening impressions:
 
Super wide, airy and open, extremely spacious 3D holographic sound stage, super detail everywhere without being etched but very musical instead, very powerful, fat and detailed bass that goes really low, pinpoint imaging and instrument separation, sweet midrange etc.
 
On the con side: A little bright but not sibilant, could be quicker with more slam. It is also interesting to note that this tube combination needs to warm up some 20 minutes to sound its best.
 
Nah, strike the blah - this is real, this is cracking!
 
British Slang: Cracking - If something is cracking, it means it is the best. Usually said without pronouncing the last "G".  Thanks, Nic.

 
Mordy....aren't you the lucky one - just 6N6P-IRs to relegate...me, it's 30P-DRs...OUCH!!!
 
These 6SN7s (and types) really are proving to be extremely versatile tubes (for us, anyway!) - glad you have also been "converted"...
 
Re your 'cons', perhaps (no, probably) those adapters - and possibly tubes? - need a good bit more run-in yet...keep us posted!
 
If your $4 tubes can perform the same as my C3GSs, you and I may well fall out!! But 'good on yer,mate!' (Glad I made my own adapters, at least!!).
 
Mar 25, 2014 at 3:51 PM Post #5,588 of 13,438
In my 6AK5 days I ordered eight Mullard M8100 tubes from a seller in the UK. One of the tubes was labeled Mullard M8100 but was a re-branded Sylvania 6AK5W tube!
 
Anyhow, I seem to remember somebody looking for the Mullard M8100/CV4010 tubes and I just realized that I have several of them.  If interested please PM me.
 
Mar 25, 2014 at 4:23 PM Post #5,589 of 13,438
  Hi mab1376,
 
Seems hard to find C3g tubes but here I came across an adapter:
 
http://www.ebay.com/itm/1x-C3G-to-6AK5-8Pin-to-7Pin-Vacuum-Tube-socket-Convert-Socket-Adapter-/301131714830?pt=Vintage_Electronics_R2&hash=item461cd9510e
 
Price seems steep - $35 for one.
 
Meanwhile I am listening to the combination of RCA 6SN7GT power tubes and a GE 6BX7GT as driver. Really very nice. GT means Grand Touring if my amp was a car. Now GT just means Glass Tube. 
 
I'm afraid that my beloved 6N6P-IR tubes will be relegated to the the dust bin......At least they have good company; some 300+ sibling tubes.
 
Here is some (blah blah) listening impressions:
 
Super wide, airy and open, extremely spacious 3D holographic sound stage, super detail everywhere without being etched but very musical instead, very powerful, fat and detailed bass that goes really low, pinpoint imaging and instrument separation, sweet midrange etc.
 
On the con side: A little bright but not sibilant, could be quicker with more slam. It is also interesting to note that this tube combination needs to warm up some 20 minutes to sound its best.
 
Nah, strike the blah - this is real, this is cracking!
 
British Slang: Cracking - If something is cracking, it means it is the best. Usually said without pronouncing the last "G".  Thanks, Nic.

 
Those are the adapters i commissioned, they just put it up for other people to purchase. they will be using hypnos1's pinout he posted a while back.
 
They are pricy indeed, but they are the first built and handmade with skills i don't posses so i feel its worth it if the c3gs is as good as hypnos1 says. Plus i can finally get rid of the spider web of wires on my unit right now.
atsmile.gif

 
Mar 25, 2014 at 4:34 PM Post #5,590 of 13,438
Hi Hypnos1,
 
I am sure the C3g tubes are better. Thing is, I am happy with the 6BX7 tube. I am going to try some similar variants if I can get a good price.
 
As you suggested I am burning in the tube. Don't know how much an effect the extender/socket saver adapters have on sound, but they look cheaply made and are only supposed to last 200 times for changing the tubes . They are not deep enough to completely insert the octal adapter 9 pin bottom pins, and there is is a 2 mm gap between the adapters. Maybe good for ventilation LOL?
 
Anyhow, the price was right for the extenders - $6.59 for four incl shipping.
 
Looking for a 6336 tube that draws 4.75A with an amplification factor of 2.7.  Wow, just found another another tube with an amplification factor of 9, the mighty 6528 tube that draws 5A. When is this going to end?
 
Artsi, we need a chart of all the 6SN7 variants (with multiplication factor) so we know what to shop for. And this chart should include the 8, 12 and 25V variants as well. Here is a beginning list:
 
6SN7
6AS7
6080
6082
6336
6528
12SX7
12SN7
6BX7
6H13C
5998
421A?
CV181
ECC32
6H8C
6N8S
1578
 
Man, I am getting tired...
 
Mar 25, 2014 at 5:23 PM Post #5,591 of 13,438
  Artsi, we need a chart of all the 6SN7 variants (with multiplication factor) so we know what to shop for. And this chart should include the 8, 12 and 25V variants as well. Here is a beginning list:
 
6SN7
6AS7
6080
6082
6336
6528
12SX7
12SN7
6BX7
6H13C
5998
421A?
CV181
ECC32
6H8C
6N8S
1578
 
Man, I am getting tired...

 
I'm not sure it is quite correct to call all these tubes "6SN7 variants", but it is true that they are all double triodes with the same pin-out as a 6SN7GT.
 
In addition to the ECC32, many folks also roll ECC33, ECC34 and ECC35 (a 6SL7 variant)
 
The 25 volt 6SN7s I am aware of:
 
25SN7
1633
13D1
 
In addition to the 25 volt 13D1, there is a 6 volt 13D2, a special quality version of the 6SN7GT, and a 13D3, which is a 9-pin variant having the same pinout as a 12A-7. The 13D series tubes appear to be unique to Brimar.....
 
And the beat goes on... :)
 
Mar 25, 2014 at 7:00 PM Post #5,592 of 13,438
I finally fixed my noisy Desktop power supply i just replaced the fan  and here it is dead quiet.Now i can't wait to receive my 12A regulator and Russian 6AS7.Can anyone please Post how to wire up 6SN7/6AS7 for Power tubes.
 
Mar 25, 2014 at 7:13 PM Post #5,593 of 13,438
   
Mordy....aren't you the lucky one - just 6N6P-IRs to relegate...me, it's 30P-DRs...OUCH!!!
 
 

I would use the 30P-DRs if you are done with them as I have no plans to upgrade yet...
 
Mar 25, 2014 at 8:49 PM Post #5,594 of 13,438
Hi i luvmusic 2,
 
The 6SN7 tubes are just plug and play with an adapter (you need two of them):
 
http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 
If the decorative ring prevents the adapters from getting seated in the sockets you need two socket savers to use as extenders. The adapters may be too wide to fit inside the diameter of the decorative ring and the pins do not reach into the sockets:
 
http://www.ebay.com/itm/2PCS-9-PIN-vaccum-TUBE-SOCKET-SAVER-FOR-12AX7-12AU7-ECC82-ECC83-tube-audio-amps-/251350602537?pt=Vintage_Electronics_R2&hash=item3a85a9d329
 
 
The 6AS7 tubes are the same pinout but they draw more current than the LD amp can handle. It is therefore imperative that you have an external power supply that supplies both tubes with the proper voltage and amperage; in this case 2.5A.  I do not have experience with this setup. You need some kind of adapter that allows you to connect the heaters of each tube separately to the appropriate voltage regulator and power supply.
 

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