Using ONLY 6SN7 for headphone amp - suggestions?

[Derro]

Hi All,

I have an abundance of 6sn7 family tubes and I wish to make a headphone amplifier using ONLY the 6sn7 throughout. I have been looking but cant find anything - Either OTL or TX output, I dont mind, I would think that the 6sn7, especially in parallel would have enough juice to supply my Sennheiser HD650.

Please, any suggestions would be most welcome.

Thanks to anyone who cares to answer!

DerrO

[Parafeed]

I made an amp that sounded rather good with HD650 a couple of years ago. 6SN7 gain stage, driving 6SN7 SRPP, with Sowter 8665 output transformer. I'll see if I can find the circuit if you're interested.

[Derro]

YES!!! ..... That is exactly what I am looking for and have also been looking at the Sowter transformers - so already I know that we could be on the right path here.

So..... if you have the time and can find that circuit that you used, I would indeed be most grateful.

If you are not still using that amp with your HD650s - what are you using these days?

Many thanks in advance,

derrO

[Parafeed]

So..... if you have the time and can find that circuit that you used, I would indeed be most grateful.

I think the circuit diagram is still on my work PC. Will try and find it tomorrow.

If you are not still using that amp with your HD650s - what are you using these days?

I have various headphone amps - DIY and commercial. The two in current use are a Zana Deux and my 300B DIY amp. The 6SN7 SRPP amp is no more. The parafeed Sowter outputs were 'borrowed' for the DIY 300B amp. (Several amps were 'destroyed' for the 300B amp. The chassis belongs to what was a Chazz 6550 amp.) You can just make out the Sowters behind the 300B's and in front of the Llundahl plate chokes.

[Voltron]

Welcome to Head-Case fellows. The DIY 300B looks grand , Parafeed. Nice work. The SinglePower MPX3 was originally all 6SN7 for gain and output, and it is an OTL design. Not sure if anyone has replicated it or traced the circuit anywhere. You could dig around or ask around to see. Good luck.

[Derro]

Thanks Parafeed.....!

Appreciate that schematic if you get time in work tomorrow!! Like the 300B also.... but lets not start on that just yet!!!

Thanks in advance.

Derro

[tkam]

6sn7s in parallel will have no problem driving higher impedance phones like the 650s but they can't drive low impedance phones very well. Of course if you add transformer coupled output to the mix then they'd have no problems with low impedance phones.

[cgraf]

Hi. I know it's a VERY long time since the last post. But I'd love to have the schematics with the "6SN7 gain stage, driving 6SN7 SRPP". Does anybody of you still have the schematics somewhere on the pc ?

Thanks for sending me an email to cgraf[at]rocketmail[dot]com

 

Best regards

Christoph

[nikongod]

SRPP=Shitty & really pathetic performance? Teh best way to build SRPP is for a very specific load (where it works great) but how would anyone know what that load is from a schematic? SRPP should reallllllllly be designed by the user for the user. 

 

If you want SEPP or (white cathode follower) which works much more good over a much more large range of loads look for schematics of the Singlepower PPx3/MPx3/Supra. 

The 3 amps are basically the same, save for the power supplies. 

The AMP circuit is basically this:

http://headwize.com/?page_id=457

with 6sn7 used instead of 6n1p. 

 

I would advocate changing R4 to be equal to your highest impedance headphones (300-600ohms, 2Kohm may be too high) because I disagree with the common method for optimizing the circuit* but any way you build it is fun and this resistor is easy to change later on. 

 

*The common way of optimization focuses purely on maximum voltage swing. Since maximum voltage swing is meaningless to most realistic uses of these amps we can safely trade some for lower output impedance, paradoxically by increasing the value of this resistor. 

Edited March 7, 2013 by nikongod

[wakibaki]

nwavguy reckons that 2V rms is sufficient with these phones.

 

This is for 0.2V pk in at 1/2 vol on pot.

 

Of course there's the question of a transformer, but there's plenty more voltage swing before clipping, you can probably tweak a lot less THD out of it, maybe some GNFB?

 

[grawk]

he also reckons his piece of shit o2 amp is the perfect headphone amplification device.

[wakibaki]

Glad you got that out of your system

 

w

[grawk]

among other things, now

[Voltron]

I hope you mean that you got that cunt out of our system, Dan.

[grawk]

that is what I mean

[Voltron]