[TonyNewman]

 

[Ramenik]

The typical setup for input tubes before the 6J5 came to prominence was a single 6SN7 socket with the 6/12/25V switch and a pair of C3g sockets. In the 6SN7 socket, other double triode tubes like the 6N7/ECC31 (with adapter) and ECC32/33/35 can be used. In the C3g sockets, other pentode tubes like the EL3N, EL11, EL8, and EL32 can be used with adapters.

Seems like the dual c3g with 6sn7 is the 'default' for most as it seems to be very flexible with the plethora of adapters available

Hey there, to play the devil’s advocate. Get a GEL3N and forget about all the tube rolling “madness”.

It is certainly very enticing. I think the gel3n looks great and elegant as well. For el3n tubes, are there only the philips tubes? As a potential first time tube user, im still deciding whether to go down this tube rolling 'rabbit hole'.

My pleasure Nik. What you didn't tell me was that you're an engineer. I would have suggested something more Frankenstein ... ish. The reason for my suggestion is because you said it's rather bewildering with all the different tubes and sockets configuration. So I thought I'll take out the c3g socket, stick in the dual 6J5 socket and for a bit of pure poetry and looks, add in a tube rectifier which is also great in sound and not just looks - the rectifier I mean.

So here are many other variations ( now you won't be confused because you're an engineer and engineers loves choices !!! ) :-

Wow ut, thanks for distilling the members amp into one message. right now the trend seems to be 6j5 with @L0rdGwyn even performing surgery on his amp.

@leftside idea also struck a chord with me as i briefly remembered being floored by a friends primaluna dialogue hp using el34 tubes to drive his tower speakers. i remembered it being very very musical sounding and enjoyable.

I choice - deary me I forgot @Xcalibur255 's choice - there's only one in the world.
OTC based on 45 tubes !!!

PICS PLEASE

 

[Ramenik]

One more question, does leaving the 2 c3g sockets empty Vs filling it together with a 6sn7 affect the output power or is it another way to tube roll?

 

[UntilThen]

Seems like the dual c3g with 6sn7 is the 'default' for most as it seems to be very flexible with the plethora of adapters available

When I started talking to Glenn about an OTL amp, there were I think 2 to 3 that were already made with a tube rectifier, one 6sn7, 2 x c3g and 6 x 6bx7gt.

The credit for the use of or proposal to have c3g in the OTL amp must go to @gibosi. He ask Glenn to incorporate the dual c3g as drivers, in addition to a single 6sn7, 2 x 6as7 and a tube rectifier for his custom Glenn OTL. This was a while ago. In those days, the OTL amps started small. I think Stavros has the first Glenn Super 9 or 10 OTL amp.

Back to the present, @Monsterzero has the most ambitious Glenn Super 10 - 1 x tube rectifier, 1 x 6sn7, 2 x c3g, 6 x 6bx7 sockets. Bare in mind that the sockets for 6bx7 are 8 pins octal, so the 6as7 or 6080 goes in there as well. I won't go into the max amperes for the Super 9 OTL amp yet. I covered that a while ago and am reluctant to retype that again. Maybe if I can find it I'll link it.

Last but not least, there is an OTL amp made for Verlocity ? .... that has a wooden cover. It's essentially a small OTL amp that uses 1 x 6sn7, 1 tube rectifier, 2 x 6as7... I think.

To those whose OTL amps I've missed.... my apologies. Can't remember everything.


It is certainly very enticing. I think the gel3n looks great and elegant as well. For el3n tubes, are there only the philips tubes? As a potential first time tube user, im still deciding whether to go down this tube rolling 'rabbit hole'.

One of the advantage of an OTC amp is refinement, quietness and the ability to drive most headphones.... and power. Glenn uses Lundahl output transformers. It's great stuff. EL3N driving EL3N was expounded by Rob even before Glenn started making the GEL3N. https://www.dhtrob.com/impressies/el3n_se_sakuma.php

Glenn's implementation of the EL3N amp is a work of art. The whole amp looks great with the Lundahl transformer and cover. Judging from those who own it and love it, it's a success. What's more, Glenn loves this amp more than any of his other amps. However Glenn has a philosophy of using cheap tubes to produce the best sounding amps. The Philips Miniwatt EL3N from Acoustics Dimensions are cheap at 25 euro each NOS with original Philips boxes. Can't get better than that.

There will be a lot of spin offs from the EL3N amp design but using other tubes.


Wow ut, thanks for distilling the members amp into one message. right now the trend seems to be 6j5 with @L0rdGwyn even performing surgery on his amp.

6j5 / L63 / 6c5 does seem to be the flavour of the month now. There are 2 advantages I can think of using those tubes. It's cheaper than the best 6sn7 or variants. Secondly it looks better than a single 6sn7. Apart from that I can't in say they are better than the best 6sn7 or ECC33, ECC35, ECC32, B65, B36, etc. Remember these tubes are predecessors of 6sn7 so they are much older. Whilst it's arguable that older tubes are better but really old tubes might not keep so well especially after 70 to 80 years... I know I'll get replies to this but it's ok.

@leftside idea also struck a chord with me as i briefly remembered being floored by a friends primaluna dialogue hp using el34 tubes to drive his tower speakers. i remembered it being very very musical sounding and enjoyable.

Yes choosing 12au7 or 12at7 as drivers or L63 / 6j5 / 6c5 as drivers or EL3N or EL11 as drivers and have EL34 as power tubes ... with Glenn's implementation of his OTC ... with Lundahl transformers.. it's a sure fire success.

My ALO Audio Studio Six as an OTC single ended triode sounded amazing with one 6sn7, dual 6V6 beam pentodes, dual OB2 tubes and a single GZ34 tube rectifier or equivalent.

PICS PLEASE

Here's a picture of @Xcalibur255 's Glenn 45 OTC amp. https://www.landfallsystems.com/index.php?content=gallery/gengal&id=21#prettyPhoto

 

[UntilThen]

Ok I'm a retard .... I need to edit the above post because I put everything together.... one second. I'll make in bold my reply.

Expand my above post and you'll see my reply in bold.

 

[UntilThen]

@leftside idea also struck a chord with me as i briefly remembered being floored by a friends primaluna dialogue hp using el34 tubes to drive his tower speakers. i remembered it being very very musical sounding and enjoyable.

I want to talk about the Primaluna Dialogue Premium HP stereo integrated amp that also has a headphone output. I have this amp in my possession for about 4 months. In that period, I was auditioning it with Ragnarok and Redgum RGI120ENR black series. All 3 amps were in my lounge room and I compare them driving my Axis LS88 floor standers.

The PL uses 6 12au7 (if I remember correctly) and 8 x KT88 !!! Just prior to selling it, I was thinking of buying 8 x EL34 and 8 x KT150 power tubes for the PL. The PL driving my floor standers sounded very neutral and solid state like. Very surprising. Of the 3 amps, I like the Redgum the most with my speakers because of the texture and bass.

However the PL with my HD800 sounded amazing ! Gives a full body tone to the otherwise clinical HD800. H800 btw sounded soooo good with the GOTL, Studio Six and WA22 (with good tubes).

These are some pictures of the PL when I had it. Sometimes I wish I hadn't sold it off. Makes a beautiful headphone amp.

 

[UntilThen]

One more question, does leaving the 2 c3g sockets empty Vs filling it together with a 6sn7 affect the output power or is it another way to tube roll?

I've tried 2 x Mullard EL32 as drivers by itself. I have also tried a single Mullard ECC33 as driver in GOTL. And I've also tried the ECC33 and dual EL32 together as drivers in the OTL amp.

First observation is that together, the amp's gain increase. Not power but gain. Apart from that I see no advantage.

Using the EL32s by themselves and the ECC33 by itself sounded beautiful. I see no reason to combine them. Remember Glenn did not originally intended for them to be combined as drivers. There are some who discovered it and seem to like it tremendously. Not to my ears.

As an aside, imagine the EC Zana Deux has a single 6SL7 and dual EL32 as input drivers.... I don't think Craig the designer of EC amps would ever design a OTL amp like the EC Zana Deux to use triplet drivers. Is it necessary? No. Does it produce better SQ? No.

 

[UntilThen]

Lastly a touchy subject but I'll touch on it anyway. In 2012, Nick in the Bottlehead Crack forum, produce a list of his favourite power tubes and rank them accordingly. http://the-key.enix.org/~krystal/review-tube-bottlehead.html

I don't follow others impressions blindly but in this instance, after 2 years of using these power tubes, I'm in total agreement with Nick as to the power tubes ranking.

There have been a lot of praise for the RCA 6as7g and RCA 6080 and Svetlana 6h13c on this thread. Whilst these are not rubbish like the original chinese tubes that came with the La Figaro 339, there are much better power tubes and not IMO - it's a fact. See Nick's ranking.

My top 4 power tubes of the 6as7 / 6080 variety are:-

GEC 6as7g
Tung Sol 5998
Bendix 6080wb
GEC 6080

If I had WE421A, it would likely be amongst the top tubes too.

In any case, I'm about to spin off from 6as7 / 6080 as I look at the pentodes as strapped triodes. Tubes such as the EL12, EL12 spez, EL34, KT66, KT77, KT88, 6L6, 5881, etc will be my next playground. Fortunately I haven't venture off into 2A3 or 300b tubes yet or maybe never because getting NOS tubes of those will be mega bucks. Besides I think EL34 and KT66 will hold a candle to the 2A3 or 300b. Of course in a Glenn's OTC, it's not just the tubes themselves....

 

[Sound Trooper]

It is certainly very enticing. I think the gel3n looks great and elegant as well. For el3n tubes, are there only the philips tubes? As a potential first time tube user, im still deciding whether to go down this tube rolling 'rabbit hole'.

Hey there, you have an open invitation to come listen to the GEL3N. Just drop me a PM.

 

[UntilThen]

Hey there, you have an open invitation to come listen to the GEL3N. Just drop me a PM.

Wait for meeeee. I'm coming.

 

[whirlwind]

Hey there, you have an open invitation to come listen to the GEL3N. Just drop me a PM.

Great invitation.

@Ramenik you may want to use this invitation , could be of great help to you...nothing like hearing it for yourself.

 

[mordy]

Mordy, try Coca Cola bottle caps. It’s nice.

Sorry - I have to avoid all sugary drinks.

 

[UntilThen]

@Monsterzero I have to stop looking at the classifieds. https://www.stereo.net.au/forums/topic/295029-fs-custom-lampizator-amber-2-r2r-volume-control/

 

[L0rdGwyn]

Here are some of the tubes I purchased last night on my 6J5 shoppping spree - early Fivre black plate 6J5GT. Have been watching this pair for a long time.



1937 Zenith (Sylvania) 6J5G, similar to @mordy 's 6C5G above, inspired me to pull the trigger. Plates are the same smooth black round plates in my Sylvania VT-94D metal base.



My own pair of Ken-Rad 6J5GT, the lead-bellies.



Been meaning to get a pair of these for a long time, they are an essential but dragged my feet since they show up quite often. STC/Brimar 6J5G, early black plate pair. I overpayed for these, passed on the opportunity for a quad for the same price in the past, but they are immaculate and in original boxes, so what the heck.



More to come

 

[L0rdGwyn]

Lastly a touchy subject but I'll touch on it anyway. In 2012, Nick in the Bottlehead Crack forum, produce a list of his favourite power tubes and rank them accordingly. http://the-key.enix.org/~krystal/review-tube-bottlehead.html

I don't follow others impressions blindly but in this instance, after 2 years of using these power tubes, I'm in total agreement with Nick as to the power tubes ranking.

There have been a lot of praise for the RCA 6as7g and RCA 6080 and Svetlana 6h13c on this thread. Whilst these are not rubbish like the original chinese tubes that came with the La Figaro 339, there are much better power tubes and not IMO - it's a fact. See Nick's ranking.

My top 4 power tubes of the 6as7 / 6080 variety are:-

GEC 6as7g
Tung Sol 5998
Bendix 6080wb
GEC 6080

If I had WE421A, it would likely be amongst the top tubes too.

In any case, I'm about to spin off from 6as7 / 6080 as I look at the pentodes as strapped triodes. Tubes such as the EL12, EL12 spez, EL34, KT66, KT77, KT88, 6L6, 5881, etc will be my next playground. Fortunately I haven't venture off into 2A3 or 300b tubes yet or maybe never because getting NOS tubes of those will be mega bucks. Besides I think EL34 and KT66 will hold a candle to the 2A3 or 300b. Of course in a Glenn's OTC, it's not just the tubes themselves....

That power tube list has probably driven the sales of low Rp output tubes for years, it's famous! But Nick forgot two tubes in the upper echelon, the Tung-Sol 7802 and Nippon Electric 6AS7G/6520

I might be the USA's chief importer of NEC 6AS7G, if I get enough, hoping to distribute some among GOTL owners, they are very nice tubes and cheap overseas.