300B Headphone Amp

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Ray P
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#76 Re: 300B Headphone Amp

Post by Ray P »

I thought it looked kind of cool...

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Dave the bass
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#77 Re: 300B Headphone Amp

Post by Dave the bass »

Ray P wrote: Tue Apr 21, 2020 8:56 pm I thought it looked kind of cool
Touch it to see if it is :)

It does look smart fo' sho'.
"The fat bourgeois and his doppelganger"
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Ray P
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#78 Re: 300B Headphone Amp

Post by Ray P »

Dave the bass wrote: Tue Apr 21, 2020 9:24 pm Touch it to see if it is :)
I did - it'll be nice on a cold winters evening!
Sorry, I couldn't resist!
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pre65
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#79 Re: 300B Headphone Amp

Post by pre65 »

Ray P wrote: Tue Apr 21, 2020 9:28 pm
Dave the bass wrote: Tue Apr 21, 2020 9:24 pm Touch it to see if it is :)
I did - it'll be nice on a cold winters evening!
You need some 833a valves Ray, the filament on it's own is 100W. (10v @ 10A). 8)
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Ray P
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#80 Re: 300B Headphone Amp

Post by Ray P »

pre65 wrote: Tue Apr 21, 2020 9:30 pm
Ray P wrote: Tue Apr 21, 2020 9:28 pm
Dave the bass wrote: Tue Apr 21, 2020 9:24 pm Touch it to see if it is :)
I did - it'll be nice on a cold winters evening!
You need some 833a valves Ray, the filament on it's own is 100W. (10v @ 10A). 8)
Nah, I've got some 6C33Cs to play with Phil! Was just going to post about them on another thread.
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IslandPink
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#81 Re: 300B Headphone Amp

Post by IslandPink »

Dave the bass wrote: Tue Apr 21, 2020 9:24 pm It does look smart fo' sho'.
Sure'nuff it is.
So smart it's almost ..sh..shho...
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Dave the bass
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#82 Re: 300B Headphone Amp

Post by Dave the bass »

IslandPink wrote: Tue Apr 21, 2020 9:56 pm
Dave the bass wrote: Tue Apr 21, 2020 9:24 pm It does look smart fo' sho'.
Sure'nuff it is.
So smart it's almost ..sh..shho...
...Bill Oddie.

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Ray P
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#83 Re: 300B Headphone Amp

Post by Ray P »

I mentioned elsewhere that this project had developed an intermittent buzz that i have to fix. As I'm going to have some dismantling and I would like to be able to run the Soekris DAC against my DSD decoders I've decided to separate the DAC and HPA components when I do the work on it. Watch this space...
Last edited by Ray P on Sun Feb 21, 2021 4:04 pm, edited 1 time in total.
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Cressy Snr
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#84 Re: 300B Headphone Amp

Post by Cressy Snr »

I fixed one and it was one of the LM317s that was causing the buzz.
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Ray P
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#85 Re: 300B Headphone Amp

Post by Ray P »

Thanks Steve, I'll bear that in mind when I get to checking it out.
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#86 Re: 300B Headphone Amp

Post by Wolfgang »

Nice development, Ray. Looking forward to hear more about how both DACs perform in comparison.

I am building an OTL headphone amp for my studio(with the 6AS7, no NFB) and was wondering how you got to the two different output impedances (32/600ohms) with the MP circuit. Do you use output transformers? As I use 3 different headphones with different impedance it might be something to consider for the one with the lowest impedance at least. Any recommendation for good OPTs?
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Ray P
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#87 Re: 300B Headphone Amp

Post by Ray P »

Wolfgang wrote: Mon Mar 01, 2021 3:38 pm ...was wondering how you got to the two different output impedances (32/600ohms) with the MP circuit. Do you use output transformers?
No transformers or other trickery, the Masterpiece can drive the 32ohm and 600 ohm headphones perfectly well, all I have done is installed two output jacks with different value output caps, something like a 3300uF Nichicon FG for 32ohms and 56uF plastic film for the 600ohms. Both my Goldring DR150 (32ohm) and BeyerDynamic DT880 (600ohm) sound really good but with a different sound so I can choose how I listen depending on the music and mood. The Goldrings have a fuller, weightier sound but the BeyerDynamics are a little lighter in tone with more detail.
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#88 Re: 300B Headphone Amp

Post by Ray P »

I've finished reworking my Transcendent Masterpiece HPA, sans integrated Soekris DAC, and with a switched attenuator installed. Eliminated the buzz that I had started to experience in its previous incarnation too. Full house of Andrew's filament supplies, two of his DHT supplies and one of his indirect supplies. B+ is courtesy of a Maida HV regulator. Looking shoddy but sounding good!

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#89 Re: 300B Headphone Amp

Post by Dave the bass »

Shoddy work there our-Ray.

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#90 Re: 300B Headphone Amp

Post by Cressy Snr »

Supreme shoddiness. :)
Sgt. Baker started talkin’ with a Bullhorn in his hand.
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