[2359glenn]

Nice. Certainly can't get that with an off-the-shelf amp. Here we have the amp designer matching the transformer for the headphones.

Well yea the closer the impedance match the better with a transformer coupled amp.
Your 300B amp is set at 32 ohms.

 

[UntilThen]

Is the GEL3N amp at 32 ohms?

 

[leftside]

Well yea the closer the impedance match the better with a transformer coupled amp.
Your 300B amp is set at 32 ohms.

The 300B amp doesn't work so well with the Stellia though. The Stellia are too sensitive and noise is generated. The 300B is dead silent with the LCD4 (and 3) though.

If your company wants to move to the Cloud, I might be able to help, but I admit hardware electronics is not my day job. I've been trying to read what I can about matching amps to headphones and found this article useful:
https://www.headphonesty.com/2019/04/headphone-impedance-demystified/

"The term ‘rule of eighths’ is used as a rough guide. Divide the headphone impedance by 8, and that is the maximum source output impedance (32 ohm headphones / 8 = 4 ohm maximum source output impedance). In practice, it isn’t that strict a rule and often success can be had with a greater range."

 

[L0rdGwyn]

I know the consensus is the 6BX7 is a bit better than the 6BL7, but these Sylvania flat-plate 6BL7 are quite good and can definitely hang with the 6BX7. I've been rolling through 6J5 drivers and I am really enjoying them as outputs so far paired with a little Peter Gabriel and some Radiohead. Don't mind my cats casually destroying my work bag.

 

[2359glenn]

The 300B amp doesn't work so well with the Stellia though. The Stellia are too sensitive and noise is generated. The 300B is dead silent with the LCD4 (and 3) though.

If your company wants to move to the Cloud, I might be able to help, but I admit hardware electronics is not my day job. I've been trying to read what I can about matching amps to headphones and found this article useful:
https://www.headphonesty.com/2019/04/headphone-impedance-demystified/

"The term ‘rule of eighths’ is used as a rough guide. Divide the headphone impedance by 8, and that is the maximum source output impedance (32 ohm headphones / 8 = 4 ohm maximum source output impedance). In practice, it isn’t that strict a rule and often success can be had with a greater range."

I can set the output impedance 2 , 4 , 8 , 16 , 32 , or 120 ohms.
You can think a transformer as a transmission with a ratio. With a 32 ohm load hooked to the 32 ohm secondary the output tube sees a perfect 7K ohm for the EL3N
If the output is 16 ohms with a 32 ohm load the tube will see 14K ohms and that will lower the power but reduce the distortion.
I can make the amp any of those impedance settings just tell me what you want.

The EL3N amp will have less noise then a 300B amp. It doesn't need special filtered DC voltage to the filament.
I have the EL3Ns running on DC to make them quieter. plus it can be run in single tube with no driver total silence just less gain.

 

[leftside]

I can set the output impedance 2 , 4 , 8 , 16 , 32 , or 120 ohms.
You can think a transformer as a transmission with a ratio. With a 32 ohm load hooked to the 32 ohm secondary the output tube sees a perfect 7K ohm for the EL3N
If the output is 16 ohms with a 32 ohm load the tube will see 14K ohms and that will lower the power but reduce the distortion.
I can make the amp any of those impedance settings just tell me what you want.

The EL3N amp will have less noise then a 300B amp. It doesn't need special filtered DC voltage to the filament.
I have the EL3Ns running on DC to make them quieter. plus it can be run in single tube with no driver total silence just less gain.

Great information Glenn. Thanks for taking the time to explain and post. Let's chat nearer the time in regards to the best transformer in this configuration for low ohm headphones such as the Stellia. Perhaps there will need to be a balance between the most appropriate load for the output tubes and for the headphones.

 

[gibosi]

Momentarily changing the topic... Picked up a somewhat rare 5U4G. This one was manufactured by Ferranti, which was a British electronics company that operated for over a century, from 1885 until it went bankrupt in 1993.

Again, per Glenn, this can be used in the OTL with four or six 6BL7 / 6BX7, but it is not powerful enough to use with 6AS7-type output tubes. And of course, it is perfectly suitable for use in the GEL3N.

I am pleased to report that it lights up but haven't had a chance to audition it. Later this evening I hope....

 

[JazzVinyl]

Hello Peeps...

Been a warm summer, been busy with lots of outdoor projects. Fired up the GOTL this evening, to make sure it still works

And happily, it does.

Using the simple tube set of an NOS Visseaux 6N7GT driver and a pair of Mullard 6080's as powers....HOW SWEET IT IS!!!

If we have any Acoustic Bass aficionado's reading, may I suggest:

Artist: Brian Bromberg
Album: Wood II

Listen carefully, kids, and all your hopes and dreams might just come true


Cheers....

.

 

[JazzVinyl]

I know the consensus is the 6BX7 is a bit better than the 6BL7, but these Sylvania flat-plate 6BL7 are quite good and can definitely hang with the 6BX7. I've been rolling through 6J5 drivers and I am really enjoying them as outputs so far paired with a little Peter Gabriel and some Radiohead. Don't mind my cats casually destroying my work bag.

I like the BL's scads better, than the BX's.

New consensus (of two).

Cheers

 

[vipervick]

Hello,

I am interested in an OTL build. I know nothing about them so far, but I was an Electronics Technician in the Navy for 20 years and a 2M Tech.

 

[UsoppNoKami]

No, no, no, yours is much much nicer. I kept your picture. It's the reason I wanted a Pheasantwood Verite. Your OTL build starting in 2 weeks? Hurray! Happy for you.

I'm using ECC33 and 6bx7s now. The OTL makes my HD800 sound amazing.

Your Pheasantwood Verite What did you use to polish it to make it so shiny?

looks the same to me mate haha

Shiny headphone photo = good lighting + Pixel 3XL camera + some Taylor's carnauba wax guitar polish + microfibre polishing cloth

 

[UsoppNoKami]

If we have any Acoustic Bass aficionado's reading, may I suggest:



Artist: Brian Bromberg
Album: Wood II

Listen carefully, kids, and all your hopes and dreams might just come true


Cheers....

.

drats, couldn't find the album on Tidal

/sad

 

[DecentLevi]

Hey guys, some may have missed my post a few days ago. Pending anything unforeseen, I believe the newer GEL3N will be my next amp. I like its' described signature of being more solid state like, ability to drive low-z cans well and even the mention of it being even more resolving than the GOTL - but someone correct me if I'm wrong? One of the headphones I'd like to drive are a planar @29 ohms and the other a somewhat power hungry new driver type @ 38ohms.

Also as I'm more familiar with OTL tube amps, what would one say is the main difference in performance / sound with an transformer coupled output? Am I right in assuming that tube rolling makes less of a difference since the tube is not the final output stage?

 

[DecentLevi]

Also @2359glenn I didn't get what you were saying about having a transformer made that can switch from 6AS7 to EL34 etc. but that it would have to be compromised with a "tap on the primary". And what about the idea of possibly having two separate transformers; one for 6AS7 or 6336 (maybe better) and one for EL34 etc.? This may potentially open a lot of doors for the EL3N amp to drive more headphones and different sound signatures, while still being able to get the best sound of EL34, EL3N etc. tubes. Or even this as a custom request amp. Feel free to reply by PM if desired.

And I would be interested to know the full specs on the GEL3N amp such as the # of tube slots for driver / power and types accepted. thanks

 

[2359glenn]

Also @2359glenn I didn't get what you were saying about having a transformer made that can switch from 6AS7 to EL34 etc. but that it would have to be compromised with a "tap on the primary". And what about the idea of possibly having two separate transformers; one for 6AS7 or 6336 (maybe better) and one for EL34 etc.? This may potentially open a lot of doors for the EL3N amp to drive more headphones and different sound signatures, while still being able to get the best sound of EL34, EL3N etc. tubes. Or even this as a custom request amp. Feel free to reply by PM if desired.

And I would be interested to know the full specs on the GEL3N amp such as the # of tube slots for driver / power and types accepted. thanks

Two output transformers? How big and heavy do you want the amp to be. The Lundahl transformers are big heavy and expensive.
Better to sell those tubes to pay for the amp or use them in the FA amp. The transformers cost more then the tubes.
In a transformer output amp the transformers have to be of the highest quality to sound great.

I can build a custom amp but the EL3N triode connected sounds as good as a 45 or 2A3 amp and they cost $20 each.
You can't beat that!!!