It has been a long road designing the Emerald Physics 600.2SE amp, but what we have finally achieved is totally worth it and an amazing sounding amp. This amp has enough power to satisfy any speaker one could imagine or need. I want to thank Jan Hofland for his help on this project as he designed the HyperSET tube buffer that feeds the 600w class D amp the audio signal. We are now finally starting production of this hybrid amp - a 600wpc Class D amp with a SET tube buffer (E88CC or NOS 6N1P). Accepts balanced or SE inputs. Selector switch for tube or SS buffer. The sound is powerful, smooth and clean with just the right secret sauce of a SET goodness. The grip on the bass is incredible. Built in integrated logic controller for graceful startup and shutdown to allow proper tube warmup and no thump. Chassis is satin finish bead blasted and black anodized CNC’d aluminum with a luxurious feel and heft (5mm thick panels all around). Real galavanometer VU meters to show power levels and quality Neutrik XLR/TRS connectors and premium Viborg pure solid copper binding posts.
Have a listen to this amp with some Vanguard bookshelf speakers:
Have a listen to this amp with some Vanguard bookshelf speakers:
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Excellent. Will you be offering the tube buffer as a DIY option? I built a dual mono block amp using two ice power 1200as2 modules which sounded amazing using a PS Audio BHK Signature preamplifier on the front end. Tried a Parasound JC2 preamplifier and the magic went away. Been looking for a tube input buffer stage ever since. Any chance I could purchase one? Thanks, Charles
We are considering offering the balanced tube buffer as a stand alone product called the HyperSET.
This was an early prototype of it:
Later versions have some logic control to allow graceful startup of the 1200AS2 after the tubes have warmed up:
If you are willing to have a balanced buffer without the tube stage (all superb OPA1656 opamps and OPA1637 balanced driver) you can get the BTSB Panel Mount buffer. There is a group buy for it. IMO, it sounds just as nice as the HyperSET.
https://www.diyaudio.com/community/threads/btsb-panel-mount-buffer.379030/#post-7040598
This was an early prototype of it:
Later versions have some logic control to allow graceful startup of the 1200AS2 after the tubes have warmed up:
If you are willing to have a balanced buffer without the tube stage (all superb OPA1656 opamps and OPA1637 balanced driver) you can get the BTSB Panel Mount buffer. There is a group buy for it. IMO, it sounds just as nice as the HyperSET.
https://www.diyaudio.com/community/threads/btsb-panel-mount-buffer.379030/#post-7040598
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I have been contemplating offering HyperSET as a DIY board. Are you talking about building if from unpopulated PCB or a RTR offering? It’s got about 200-300 components so not a walk in the park.
Current version has a Wurth IDC ribbon cable connector for optional panel mounted volume pot and also open collector logic for ensuring graceful startup and shutdown of an amp that it is connected to. Oh, and there is a switch that allows the tube stage to be bypassed for purely solid state operation.
Current version has a Wurth IDC ribbon cable connector for optional panel mounted volume pot and also open collector logic for ensuring graceful startup and shutdown of an amp that it is connected to. Oh, and there is a switch that allows the tube stage to be bypassed for purely solid state operation.
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X,
I’m sure most folks would be interested in RTR, but that would depend on cost too.
I am interested in just blank board, recommendations, schematic, BOM, etc…but you should gauge interest first. I would build it slowly. A little at a time to minimize mistakes. No use for you to put all the effort unless there is interest.
Tell us more. What 9 pin tubes? E88CC/6DJ8? What other tubes are possible ? Gain options. Peak to peak voltage swing, Output Z, etc….I figure the output Z would be super low since the opamp buffer is there. Personally I would build it as a dedicated tube preamp using a remote stepped attenuator or pot with SE/ balanced input and SE + balanced output. Something to compete with Schiit Freya.
I’ve never seen a mostly SMD based tube circuit hence the interest. Since I’ve already built the headphone protect board and panel mount BTSB’s, the 200-300 parts count doesn’t bother me. It just takes more time and do little bits at a time. Probably a few weekends.
Best,
Anand.
I’m sure most folks would be interested in RTR, but that would depend on cost too.
I am interested in just blank board, recommendations, schematic, BOM, etc…but you should gauge interest first. I would build it slowly. A little at a time to minimize mistakes. No use for you to put all the effort unless there is interest.
Tell us more. What 9 pin tubes? E88CC/6DJ8? What other tubes are possible ? Gain options. Peak to peak voltage swing, Output Z, etc….I figure the output Z would be super low since the opamp buffer is there. Personally I would build it as a dedicated tube preamp using a remote stepped attenuator or pot with SE/ balanced input and SE + balanced output. Something to compete with Schiit Freya.
I’ve never seen a mostly SMD based tube circuit hence the interest. Since I’ve already built the headphone protect board and panel mount BTSB’s, the 200-300 parts count doesn’t bother me. It just takes more time and do little bits at a time. Probably a few weekends.
Best,
Anand.
Hi Anand,
The balanced output driver is OPA1637 so same capability as the BTSB panel mount. I think possibly +/-30vpp in balanced output. The SE output driver is OPA1656. Similar gain settings of 0/6/14/20dB but semi adjustable as you have done on BTSB. It uses E88CC but I use Russian NOS 6N1P which I find sounds better and measures slightly better. It is also supposed to be bulletproof in terms of durability and long life. About 0.002% THD for 2Vrms into 10k load with dominant second harmonic and descending higher orders. You can think of it as a BTSB with a tube buffer stage in between. There is an on-board 90v DCDC step up generator for the B+. There is remote standby/on capability which lets you control the filament and HV independent of the main +/-15v rails for the opamp (always on as long as 12v power is fed to it).
If you pair it with a BTSB Panel Mount Lite, that will give you the RCA and XLR/TRS jacks with balanced auto switching capability (self sensing relays) much like the BTSB panel mount.
The balanced output driver is OPA1637 so same capability as the BTSB panel mount. I think possibly +/-30vpp in balanced output. The SE output driver is OPA1656. Similar gain settings of 0/6/14/20dB but semi adjustable as you have done on BTSB. It uses E88CC but I use Russian NOS 6N1P which I find sounds better and measures slightly better. It is also supposed to be bulletproof in terms of durability and long life. About 0.002% THD for 2Vrms into 10k load with dominant second harmonic and descending higher orders. You can think of it as a BTSB with a tube buffer stage in between. There is an on-board 90v DCDC step up generator for the B+. There is remote standby/on capability which lets you control the filament and HV independent of the main +/-15v rails for the opamp (always on as long as 12v power is fed to it).
If you pair it with a BTSB Panel Mount Lite, that will give you the RCA and XLR/TRS jacks with balanced auto switching capability (self sensing relays) much like the BTSB panel mount.
This looks fun to me.
But clearly from the dearth of replies from others…I am alone
. I noticed this happened on the headphone protect board you offered a few years back. Are those sales stronger now?
The ball is back in your court X. You have some decisions to make!
What is the market viability for this board design? (I’m sure this thought runs through your mind frequently on this forum!).
Perhaps offer a few blank boards on your Etsy site but with very detailed schematics, and a few more closeup photos (I would divide the board up into quadrants or actually six parts and take closeup photos of each part). BOM as well. Silkscreen overlay with drill hole placement pattern. And perhaps a short summary of test points, and order of testing. This can all be offered to the buyers who buy but via email only. It protects your IP.
At the end of the day, the way I look at it, this is basically a tube buffer stage sandwiched in a BTSB. A little “flavoring” and 6N1P or 6DJ8/ECC88 tube rolling so to speak. But it appears that you need to make a decision early on whether you want to use the 6N1P (which has a substantially higher dynamic plate impedance) or the 6DJ8 variants as the biasing is a little different. And changing that involves playing with 0603 SMD resistors. Some will like that (me). Others will freak out and get emotional. Personally, I would love to be able to choose other 9 pin tubes (that are compatible with the schematic) but I realize some have much higher heater requirements and that may be an issue with this design. In example, 6H30 and 6N6P.
Just some thoughts, and me rambling.
Best,
Anand.
But clearly from the dearth of replies from others…I am alone
. I noticed this happened on the headphone protect board you offered a few years back. Are those sales stronger now?The ball is back in your court X. You have some decisions to make!
What is the market viability for this board design? (I’m sure this thought runs through your mind frequently on this forum!).
Perhaps offer a few blank boards on your Etsy site but with very detailed schematics, and a few more closeup photos (I would divide the board up into quadrants or actually six parts and take closeup photos of each part). BOM as well. Silkscreen overlay with drill hole placement pattern. And perhaps a short summary of test points, and order of testing. This can all be offered to the buyers who buy but via email only. It protects your IP.
At the end of the day, the way I look at it, this is basically a tube buffer stage sandwiched in a BTSB. A little “flavoring” and 6N1P or 6DJ8/ECC88 tube rolling so to speak. But it appears that you need to make a decision early on whether you want to use the 6N1P (which has a substantially higher dynamic plate impedance) or the 6DJ8 variants as the biasing is a little different. And changing that involves playing with 0603 SMD resistors. Some will like that (me). Others will freak out and get emotional. Personally, I would love to be able to choose other 9 pin tubes (that are compatible with the schematic) but I realize some have much higher heater requirements and that may be an issue with this design. In example, 6H30 and 6N6P.
Just some thoughts, and me rambling
.Best,
Anand.
It’s describe above in this thread.
Yes, I designed the overall amp and specified the IcePower 1200AS2 as the class D core.
The HyperSET buffer was custom designed by Jhofland for this amp and is based on the BTSB buffer but with an E88CC SE Class A tube stage in between to provide the sonic character of a clean low distortion tube amp with dominant second harmonic profile and yet low THD of 0.002%.
There is custom designed logic to provide smooth startup and shutdown.
Yes, I designed the overall amp and specified the IcePower 1200AS2 as the class D core.
The HyperSET buffer was custom designed by Jhofland for this amp and is based on the BTSB buffer but with an E88CC SE Class A tube stage in between to provide the sonic character of a clean low distortion tube amp with dominant second harmonic profile and yet low THD of 0.002%.
There is custom designed logic to provide smooth startup and shutdown.
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are smd I would be for RTR.