[baronbeehive]

It's still MrCurwens original design but it will be a first trying to get this much power out of this design. That's the reason it's going to be a bigger chassis. To accommodate for larger heat sinks. Gyrator plate loads are great for getting the tubes a flat load line. The downside is that the gyrator FET needs to dissipate as much heat as the tube. If I run the tube at 10W the FET also dissipates 10W, hence big heat sinks =)

Very exciting! A flat load line means zero distortion potentially, that will be interesting to pair that with tube sound, I can't imagine what the end result could be. Could be tube rollers heaven haha!

My APPJ Set amp outputs 3.5W and is one of the trendy low powered SET's so it will be interesting to try to get that extra power out just to see what happens!
.

 

[Bonddam]

Tomas are targeting the power for the Susvara and 1266 in the 50 ohm range?

 

[SonicTrance]

Tomas are targeting the power for the Susvara and 1266 in the 50 ohm range?

Power output in the 50 ohm range will also be much higher than with Oblivion/Citadel, but most power will be had into 8 ohms to power speakers. There's no reliable way to calculate exactly how much power, unfortunately. I need to build it and measure. We'll see how much power I (safely) can get out of it

 

[MaggotBrain]

Quick question - what are the dimensions of the Citadel? Trying to figure out how I have to shuffle my gear around with one coming in late this week. The measurements may dictate having to buy some longer cables so hoping to find out soon. Thank you so much.

 

[SonicTrance]

Quick question - what are the dimensions of the Citadel? Trying to figure out how I have to shuffle my gear around with one coming in late this week. The measurements may dictate having to buy some longer cables so hoping to find out soon. Thank you so much.

The dimensions are specified in the website. I'm not allowed to link it but it's not hard to find.

 

[MaggotBrain]

The dimensions are specified in the website. I'm not allowed to link it but it's not hard to find.

I hope the sound is as impressive as the size! Turns out I could move stuff around so the amp can be on top and well ventilated so I will be good to go.

 

[SonicTrance]

Do you have the instructions for it? I can PM them to you otherwise.

 

[MaggotBrain]

Do you have the instructions for it? I can PM them to you otherwise.

The seller was kind enough to email them to me, but thank you for your consideration. I am sure I will have questions in the future given that I’m a tube newbie!

 

[paradoxper]

Power output in the 50 ohm range will also be much higher than with Oblivion/Citadel, but most power will be had into 8 ohms to power speakers. There's no reliable way to calculate exactly how much power, unfortunately. I need to build it and measure. We'll see how much power I (safely) can get out of it

You must have an estimated range you are hoping to shoot for into 8 ohms at least.

 

[SonicTrance]

You must have an estimated range you are hoping to shoot for into 8 ohms at least.

Yes, of course. I shoot for around 8 W into 8 ohms. That should be able to drive most speakers to ear bursting levels. The thing is that the output transformers I use doesn't have specified secondary inductance, it varies depending on the load (and frequency of the signal). Because of that I can't simulate with different loads in LTspice. I do have some known points (from previous testing) and 8 W into 8 ohms should be doable. Testing when building is the way to go.

 

[paradoxper]

Yes, of course. I shoot for around 8 W into 8 ohms. That should be able to drive most speakers to ear bursting levels. The thing is that the output transformers I use doesn't have specified secondary inductance, it varies depending on the load (and frequency of the signal). Because of that I can't simulate with different loads in LTspice. I do have some known points (from previous testing) and 8 W into 8 ohms should be doable. Testing when building is the way to go.

So that's nominally double what the Citadel outputs. However, this more with speakers in-mind. 4-ish watts isn't too bad for those pesky planars though.

 

[DecentLevi]

Power output in the 50 ohm range will also be much higher than with Oblivion/Citadel, but most power will be had into 8 ohms to power speakers. There's no reliable way to calculate exactly how much power, unfortunately. I need to build it and measure. We'll see how much power I (safely) can get out of it

Looks like a fantastic design on the way, and maybe I'm lucky to have still waited. Someone on here mentioned they didn't like the Oblivion or Citadel pairing with the HEDDphone - I would be very interested to see the pairing tried again being the new amp is supposed to put out even more power around 50 ohms, which is just what those need. It should also make a good pairing for the Rosson Audio Rad-0 planars.

Also SonicTrance, another word in favor of the possibility to use EL12 tubes in the future amp. Compatibility with this tube type would also open other doors possibly with EL11 and using adapters EL12 Spez, EL3N and maybe even the great KT66 / 88 / 150 tubes! These tubes are favored by basically all who try them (including me) and AFAIK most measure well. Also I have a 'bias' that larger tubes sound better. It may not have any scientific backing, but my personal experience with tubes has always favored the larger ones for a larger soundstage and more sense of 'air' and even instrument separation. Miniature 9-pin tubes are great as well for more of a detailed / precise and punchy sound so each have their merits.

 

[SonicTrance]

Looks like a fantastic design on the way, and maybe I'm lucky to have still waited. Someone on here mentioned they didn't like the Oblivion or Citadel pairing with the HEDDphone - I would be very interested to see the pairing tried again being the new amp is supposed to put out even more power around 50 ohms, which is just what those need. It should also make a good pairing for the Rosson Audio Rad-0 planars.

Also SonicTrance, another word in favor of the possibility to use EL12 tubes in the future amp. Compatibility with this tube type would also open other doors possibly with EL11 and using adapters EL12 Spez, EL3N and maybe even the great KT66 / 88 / 150 tubes! These tubes are favored by basically all who try them (including me) and AFAIK most measure well. Also I have a 'bias' that larger tubes sound better. It may not have any scientific backing, but my personal experience with tubes has always favored the larger ones for a larger soundstage and more sense of 'air' and even instrument separation. Miniature 9-pin tubes are great as well for more of a detailed / precise and punchy sound so each have their merits.

The first Infinity I'll build will have the 6N2P (or 6AV6) input and 6P36S output. I've chosen those two tubes with regards to internal resistance, gain, availability and cost. In that amp there's no possibility for tube rolling as I use grid (fixed) bias. With that said I have no problem building a custom amp using other tubes! Keep in mind though that the amp will sound best if designed around a certain tube.

 

[DecentLevi]

Thanks @SonicTrance I love how you focus on the best quality / design possible and without compromises... go big or go home, as the saying goes I will definitely keep you in mind for a possible future build around certain tubes, or would order one of the newer models coming out - depending on how things are goin.

Truth be told guys I'm still waiting on a darn Glenn tube amp! That's why I've yet to order any Ultrasonic amp. Already well over one year and although I've gotten a hint here & there about a possible timeline, still no build has begun! I don't want to speak lowly of Glenn as he is a very noble man and master craftsman, but just thought I'd put this out here to see what anyone here thinks. Both 2359Glenn and Ultrasonic amps cost around the same (considering my customization options) and from what I gather from the impeccable reviews on this thread, the Ultrasonic amps are incomparable to basically anything out there bar-none. For me personally however I have a 'lot invested' in the potential Glenn amp - even though there's no end in sight I'm not wanting to jump ship there, having around $1,000 already invested in rare / top-flight vintage tubes, as well as a huge box of handcrafted adapters specifically for it. Going for a an amp here and getting in a new waiting que though would possibly delay me even more in the long run. Feel free to be frank and let me know any opinions on all this.

 

[SonicTrance]

Thanks @SonicTrance I love how you focus on the best quality / design possible and without compromises... go big or go home, as the saying goes I will definitely keep you in mind for a possible future build around certain tubes, or would order one of the newer models coming out - depending on how things are goin.

Going for a an amp here and getting in a new waiting que though would possibly delay me even more in the long run.

Thanks for the kind words! I won't comment on your Glenn build but if you want an amp from me I can build it in February!