[mordy]

Took a bit of a break from tubes and now slowly returning to tube rolling only to find that i kinda forgot stuff over time but luckily i took notes on what tube goes with what adapter because it can be problematic so i need a good refresher lol . By the way tonight's setup . 5998 as power tubes , Ken Rad 6SN7GT VT-231 as drivers and a Philips Miniwatt GZ32 Rectifier .Sorry not a Glenn Amp but tubes are tubes lol .

Hi Mikelap,
Good to hear from you! It is so interesting to me that the old gang from the Little Dot days all upgraded to better amps. It was a good learning experience and we did some wild tube rolling and experimentation - I don't think any of us are ready to cut off pins and use jumper wires in the sockets any more!

 

[ashwinvyas1981]

Well since GOTL was not coming soon enough, so needed something to satisfy the craving for toobs. I ended up with this beautiful custom 45 DHT amp called Otomon. The price to performance ratio is off the charts & these 45s are phenomenal. Great synergy with Arya as well as Auteurs. This uses 717A as drivers & 5Z3, 80s' as rectifier.
EDIT: In transit it was damaged beyond recognition but a genius here in India repaired it, that is the reason the structural stiffness is not there now. The Trafo wt is doing its job (the slight tilt) . Planning to add some support to compensate this shortly.

 

[hpamdr]

Took a bit of a break from tubes and now slowly returning to tube rolling only to find that i kinda forgot stuff over time but luckily i took notes on what tube goes with what adapter because it can be problematic so i need a good refresher lol . By the way tonight's setup . 5998 as power tubes , Ken Rad 6SN7GT VT-231 as drivers and a Philips Miniwatt GZ32 Rectifier .Sorry not a Glenn Amp but tubes are tubes lol .

Hi Mike,
You are on the dark side with both KR VT-231 and 5998.. With HD800s it is a very good setup for 70s pop/folk or blues.

I've also stopped to do too many tube experiment. Anyhow, I defined a kind of neutral setup with GEC 6080 as power and Visseaux 6J5MG as driver on Euforia driving HD800s..
With this setup as reference, I'm refreshing my notes about tube combination slowly and not with tube rolling excitement.
And guess what, standard tube combination is not that bad...

 

[MIKELAP]

6H12C data sheet

I can't read Russian, but it appears that the heater is 0.9 amp and the amplification factor is 17, so not quite equal to the 6BL7, but close. A 6-pack is working fine for me.

Received 2 pairs of Melz 6H12C (1964?)printed 64 next to Melz .WA22 drivers can handle up to 1A\channel .Like them pretty clean sounding not the most bassy but still nice .

 

[triod750]

Received 2 pairs of Melz 6H12C (1964?)printed 64 next to Melz .WA22 drivers can handle up to 1A\channel .Like them pretty clean sounding not the most bassy but still nice .

I suspect that you will find the year -62 on the glass at about five o'clock with the 'M' for Melz in the center. The V M 64 is something else I think.

 

[mordy]

I suspect that you will find the year -62 on the glass at about five o'clock with the 'M' for Melz in the center. The V M 64 is something else I think.

It also has the month in Roman numerals - mine says VIII-62 (August). I like these tubes - very even frequency response and very detailed and bring clarity to the presentation.
As always YMMV - every amp is different and the same tube may sound different in the WOO compared to the GOTL.

 

[gibosi]

Received 2 pairs of Melz 6H12C (1964?)printed 64 next to Melz .WA22 drivers can handle up to 1A\channel .Like them pretty clean sounding not the most bassy but still nice .

Yes, your 6H12C are 1962 vintage. And I think I see a pair of GE 5998A and a Mullard GZ32?

 

[gibosi]

Received 2 pairs of Melz 6H12C (1964?)printed 64 next to Melz .WA22 drivers can handle up to 1A\channel .Like them pretty clean sounding not the most bassy but still nice .

And I would encourage you to run four as output tubes. I use six, and I find them to be very transparent and detailed in this position.

 

[whirlwind]

I totally love the Mullard GZ32...it flies under the radar so to speak as far as rectifiers go.

I need to snag a couple more of these, but am pretty dang broke at the moment

 

[gibosi]

I totally love the Mullard GZ32...it flies under the radar so to speak as far as rectifiers go.

I need to snag a couple more of these, but am pretty dang broke at the moment

And I agree. It's usually not all that expensive and of Mullard's 5-volt rectifers, I much prefer the GZ32 to the GZ33 or GZ37.

 

[MIKELAP]

And I would encourage you to run four as output tubes. I use six, and I find them to be very transparent and detailed in this position.

I haven't checked yet but do they have adapters for this ?. I also have these double 6BL7 adapters that i used in the power tube section ,by any chance would the 6H12C work with these adapters ? Since they compare them to the 6BL7

 

[triod750]

6H12C has the same pinout as 6SN7.

Should have said that 6BL7 has the same pinout too.

 

[MIKELAP]

Yes, your 6H12C are 1962 vintage. And I think I see a pair of GE 5998A and a Mullard GZ32?

Actually the GE's are 6AS7GA and the GZ32(Blackburn 1960)like you say is Mullard made labeled Philips Miniwatt

 

[MIKELAP]

I haven't checked yet but do they have adapters for this ?. I also have these double 6BL7 adapters that i used in the power tube section ,by any chance would the 6H12C work with these adapters ? Since they compare them to the 6BL7

Ok i found the answer 7 pages back. Gibosi you had answered this question lol . Im getting old 65 this year . Thanks lol

 

[gibosi]

I haven't checked yet but do they have adapters for this ?. I also have these double 6BL7 adapters that i used in the power tube section ,by any chance would the 6H12C work with these adapters ? Since they compare them to the 6BL7

Yes, you can use the same adapter for 6BX7, 6BL7 and 6H12C. So I would encourage you to try four 6H12C as output tubes and a pair of black-glass Ken-Rad 6SN7GT as drivers. That will give you the bass you were missing.