# Paul: new FET amplifier design

**URL:** <https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058>\
**Category:** Amplifiers\
**Created:** [June 19, 2023, 7:50am UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058 "2023-06-19T07:50:42Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Nikos](https://avatars.discourse-cdn.com/v4/letter/n/34f0e0/32.png) [@Nikos](https://forum.psaudio.com/u/Nikos)\
**Post date:** [June 19, 2023, 7:50am UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/1 "2023-06-19T07:50:42Z")

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Paul,  
in your youtube videos you have mentioned a couple of times a new FET power amplifier design that sonically challenges the existing hybrid BHK amps. Would you care to give some more information on this design?

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**Author:** ![jazznut](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jazznut](https://forum.psaudio.com/u/jazznut)\
**Post date:** [June 19, 2023, 10:17am UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/2 "2023-06-19T10:17:22Z")

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Isn’t this what Pass has done decades ago? I remember, my Aleph 0 monos at the time had their reputation because of the FET design.

At the time FET were already known to replicate certain tube characteristics (which those Aleph’s did). I bet Bascom knew that, so it would be interesting what’s the new discovery Paul made with MOSFETs.

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**Author:** ![mark-d](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/mark-d/32/20_2.png) [@mark-d](https://forum.psaudio.com/u/mark-d)\
**Post date:** [June 19, 2023, 2:07pm UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/3 "2023-06-19T14:07:51Z")

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Coda has their own FET design also. Outstanding sound quality in all regards!

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**Author:** ![jazznut](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jazznut](https://forum.psaudio.com/u/jazznut)\
**Post date:** [June 19, 2023, 2:26pm UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/4 "2023-06-19T14:26:04Z")

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Well Gryphon owners will miss low frequency oomph as far as I know FETs, but maybe the correlation is wrong…and Gryphon owners will miss this from most amps 😉

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**Author:** ![owlsalum](https://avatars.discourse-cdn.com/v4/letter/o/e47c2d/32.png) [@owlsalum](https://forum.psaudio.com/u/owlsalum)\
**Post date:** [June 19, 2023, 3:20pm UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/5 "2023-06-19T15:20:35Z")

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? The BHK250 utilizes a MOSFET output stage. Are you alluding to an all FET SS design? Use of MOSFETs in all SS power amplifiers is anything but new. For example, David Belles (Power Modules) has based all of his power amplifiers over the years on a tried and true MOSFET output stage.

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**Author:** ![Theo](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/theo/32/86253_2.png) [@Theo](https://forum.psaudio.com/u/Theo)\
**Post date:** [June 19, 2023, 7:03pm UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/6 "2023-06-19T19:03:40Z")

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My curiosity about Paul’s “New and Promising SS Design” comments (see **[PS Audio and GaN-based Class D - #33 by Theo](https://forum.psaudio.com/t/ps-audio-and-gan-based-class-d/11636/33)**) are about the recent “GaNFET Transistor” amp circuit typologies existing in the market place (like my power amp, the _**[https://orchardaudio.com/product/starkrismon\_stereo\_ultra\_500w\_stereo\_amp/](https://orchardaudio.com/product/starkrismon_stereo_ultra_500w_stereo_amp/)**_)!!!

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**Author:** ![paul172](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/paul172/32/308402_2.png) [@paul172](https://forum.psaudio.com/u/paul172)\
**Post date:** [June 19, 2023, 9:53pm UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/7 "2023-06-19T21:53:42Z")

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> [@jazznut](#):
>
> Well Gryphon owners will miss low frequency oomph as far as I know FETs,

I’m entry level Gryphon and I’m not missing any low frequency oomph. I’ve never had so much low frequency oomph! The sound is powerful and effortless.

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**Author:** ![jazznut](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jazznut](https://forum.psaudio.com/u/jazznut)\
**Post date:** [June 19, 2023, 10:04pm UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/8 "2023-06-19T22:04:37Z")

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That’s what I mean…Gryphon owners will miss it from FET amps (not from their Gryphon Sanken bipolars) 😉 At least when speaking of heavy A biased power amps, but for sure the characteristic goes through the whole line. When I had a Gryphon power amp, I didn’t need subs in the room at the time. The Pass (also full Class A) were very different.

One can argue what’s more neutral, but one can get great sound (with very different strengths/weaknesses) from both concepts.

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**Author:** ![Nikos](https://avatars.discourse-cdn.com/v4/letter/n/34f0e0/32.png) [@Nikos](https://forum.psaudio.com/u/Nikos)\
**Post date:** [May 4, 2024, 9:16pm UTC](https://forum.psaudio.com/t/paul-new-fet-amplifier-design/34058/9 "2024-05-04T21:16:48Z")

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A new FET amplifier was this time mentioned in a PS Audio factory tour given by Paul to Stereo+ magazine editor Ståle Winterkjær. It is being designed by Bob Stadtherr. Paul refers to it as the A B amplifier.

[![](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/9/2/929ba67023459bdc135dc7f7819ae3c4249467d7.jpeg "PS Audio secrets to hifi-sucess") ](https://www.youtube.com/watch?v=Qid6J2VjDHQ&t=80s)
