Dennis Had Inspire Amps

[Analog Addict]

Been absentee lately building an amp. PSE 45 with voltage regulator tubes instead of Zener diodes. Heading over to the shop to listen and bench test it. Dennis is chomping at the bit to listen to it. If he really likes it, maybe he will offer his own version....





What can I say, I love that tube glow!

[Rosco65]

I don't think you have enough tubes for a 3wpc amp.

[FloridaBoy]

Originally Posted by Rosco65

I don't think you have enough tubes for a 3wpc amp.

Yeah, one more tube and it will probably toast marshmallows.



I think the VR tubes will make it sound more powerful that 3 watts.

[Analog Addict]

Sounds like Diana Krall is sitting right in front of us...

[Simonatsea]

Wow! Good work! That is one impressive amp, do you have any upskirt shots?
Can this power supply be applied to PSE amps using higher output tubes?
Love to hear how it compared to its stable mates. What speakers were you auditioning it with?

[Analog Addict]

Originally Posted by Simonatsea

Wow! Good work! That is one impressive amp, do you have any upskirt shots?
Can this power supply be applied to PSE amps using higher output tubes?
Love to hear how it compared to its stable mates. What speakers were you auditioning it with?

Here's the upskirt shot....



My work has a long way to go to match the neatness of Dennis' layouts, but since I've built less than 10 of my own scratch builds, and Dennis has prolly built 1000's, I'm making progress. It always helps to learn at the feet of the master.

The power supply is a standard type, just over engineered. Using TDSL to model it, I think the ripple voltage is supposed to be on the order of 500 nV. It has 5 filter stages, including two chokes.

Here's the PS schematic....



Pardon the oil stain. I absentmindedly tossed a gun cleaning rag on top of it. One of the hazards of having a multi purpose man cave.

As far as the sound, Dennis says it's still an old man's amp, only with a splash of Geritol thrown in. The best way I can describe it is that both amps let the true nature of the different types of output tubes shine through. However, compared to a single 45 per channel SET amp, it has more presence and authority, with a mid range that drips honey and syrup. Perhaps not everyone's cup of tea, but it suits me, dare I say it, to a T. Think of a regular 45 amp on steroids. We listened to it on the standard shop speakers. I have a few more minor changes to make and it's going into my main system....

[Comzee]

I wish this forum supported likes or thumbs up. Anyway, looks amazing @Analog Addict, I hope one day to design my own amps.
Quite beautiful with that tube glow!

I have a few updates on tube opinions with my fire-bottle.
#1 New stock Tung-Sol 6550 crush Tung-Sol 6550 NOS (at least the NOS I bought).
#2 we6sn7 initial impression is cross between psvane cv181 mkii and shuguang cv181-t sounds. I'll have to listen more, but it's not a revelation, anybody with either cv181 isn't missing out.

[Musica Amantem]

Originally Posted by Comzee

I wish this forum supported likes or thumbs up. Anyway, looks amazing @Analog Addict, I hope one day to design my own amps.
Quite beautiful with that tube glow!

I have a few updates on tube opinions with my fire-bottle.
#1 New stock Tung-Sol 6550 crush Tung-Sol 6550 NOS (at least the NOS I bought).
#2 we6sn7 initial impression is cross between psvane cv181 mkii and shuguang cv181-t sounds. I'll have to listen more, but it's not a revelation, anybody with either cv181 isn't missing out.

Interesting results. I have both CV-181's and plan to get the CV-181 Z from Shu Guang. I believe FloridaBoy is testing the We 6SN7 also, I'm sure he'll provide his own opinion.

Curiously, I find the Psvane CV-181 T-II too revealing, almost strident on top except with the KT-66 Z (with which it is great), while the CV-181 T from Shu Guang seems more laid back. I'm hoping to find the CV-181 Z a middle-of-the road between these two. Then again, the input tube creates synergies with the right output tube, so there are no absolute input tube winners IMO. BTW, I'm still trying to match the misterious GL KT-77 with the ideal input tube. I have several iterations to try yet (NOS and new production).

[FloridaBoy]

Originally Posted by Comzee

I wish this forum supported likes or thumbs up. Anyway, looks amazing @Analog Addict, I hope one day to design my own amps.
Quite beautiful with that tube glow!

I have a few updates on tube opinions with my fire-bottle.
#1 New stock Tung-Sol 6550 crush Tung-Sol 6550 NOS (at least the NOS I bought).
#2 we6sn7 initial impression is cross between psvane cv181 mkii and shuguang cv181-t sounds. I'll have to listen more, but it's not a revelation, anybody with either cv181 isn't missing out.

I agree on the TS-6550. I have a Shuguang WE 6SN7 coming. The Chinese CV-181's are fine tubes.

[Analog Addict]

Originally Posted by FloridaBoy

I agree on the TS-6550. I have a Shuguang WE 6SN7 coming. The Chinese CV-181's are fine tubes.

I will have to begrudgingly agree with you. Dennis gifted me with a PSvane CV 181 during our last listening session, and I'll have to say it sounds really good, and this is coming from a confirmed old stock toob snob. I will have to continue to evaluate it in the new amp and compare it to some of the 1940's era VT-231s....