Dennis Had Inspire Amps

[BearCityUSA]

Originally Posted by robert_kc

I wonder how this parallel KT77 SE amp (20wpc) compares with the KT88 SE amp that he recently built (single output tube per channel) that produces 17wpc?

Does anyone know if he's ever added 4 ohm speaker taps?

My 2013 KT has 4 and 8 ohm taps.

http://i1255.photobucket.com/albums/...psdnqurd7f.jpg

[FloridaBoy]

Originally Posted by guitardave

How do I order one of these? I would assume I can order one, correct? But how, where...

You can reach Dennis via the auction site Radioman731 is his ID.

[x3workshop]

Originally Posted by FloridaBoy

Have you tries swapping cables on the source that you were using? I've had some issues on start up but it seemed to be the tubes in the amp.

Have you swapped the 6BX7?

It's ceased since I let it warm for at least 10 minutes.

[robert_kc]

Originally Posted by BearCityUSA

My 2013 KT has 4 and 8 ohm taps.

http://i1255.photobucket.com/albums/...psdnqurd7f.jpg

Thanks for the information. That's very interesting. In one of my systems I have 4 ohm speakers. If Dennis ever comes out with a 211/845 amp that has 4 and 8 ohm taps, and good input sensitivity - I may be tempted to buy a second Inspire amp.

[Simonatsea]

Originally Posted by robert_kc

I wonder how this parallel KT77 SE amp (20wpc) compares with the KT88 SE amp that he recently built (single output tube per channel) that produces 17wpc? Does anyone know if he's ever added 4 ohm speaker taps?

I believe

[Simonatsea]

[QUOTE="Simonatsea;792780"] I believe his standard output transformers have both 4 ohm and 8 ohm outputs, you just have to swap the internal connections to the speaker taps. I have special 16 ohm output trannies that only have the one impedance.

[Musica Amantem]

Originally Posted by robert_kc

I wonder how this parallel KT77 SE amp (20wpc) compares with the KT88 SE amp that he recently built (single output tube per channel) that produces 17wpc?

Does anyone know if he's ever added 4 ohm speaker taps?

The main difference is their design conception:

That particular KT-88 is probably a SEP (single-ended Pentode /Beam-Tetrode) thus the extra power of 17 Watts relative to the SET option.

The latter (KT-77 at 20 Watts) is a Push-Pull of the parallel tube variation.

Although implementation rules results, OTBE the SEP is better sounding. It is a matter of tradeoffs btw power/convenience vs midrange sound quality.

I personally prefer the SET type, where the Beam-Tetrode/Pentode is strapped as a Triode in single-ended configuration (like my Inspire amp), with the best midrange of those three and still very dynamic over a true DHT SET (which uses exclusively Triodes instead of Pentodes or Beam Tetrodes in single-ended configuration), which in turn excels in midrange sound.

[Analog Addict]

Originally Posted by Musica Amantem

The main difference is their design conception:

The KT-88 is probably a SEP (single-ended Pentode /Beam-Tetrode) thus the extra power of 17 Watts relative to the SET option.

The latter (KT-77 at 20 Watts) is a Push-Pull of the parallel tube variation.

Although implementation rules results, OTBE the SEP is better sounding. It is a matter of tradeoffs btw power/convenience vs midrange sound quality.

I personally prefer the SET type, where the Beam-Tetrode is strapped as a Triode in single-ended configuration (like my Inspire amp), with the best midrange of those three and still very dynamic over a true DHT SET (which uses exclusively Triodes instead of Pentodes or Beam Tetrodes in single-ended configuration), which excels in midrange sound.

Don't count on it. I don't remember the last time Dennis built a PP design. It is most likely a parallel SEP design

[BearCityUSA]

Originally Posted by Analog Addict

Don't count on it. I don't remember the last time Dennis built a PP design. It is most likely a parallel SEP design

Agree. Dennis sent me the same photos a few weeks ago. I posted links here. His description was "parallel single ended". He even calls it the PSE. He had some IFAs a while back described the same way with el-84s

My discussions with Dennis as well lead me to believe he will not be doing any PP designs in his 'retirement'.

[Musica Amantem]

Originally Posted by Analog Addict

Don't count on it. I don't remember the last time Dennis built a PP design. It is most likely a parallel SEP design

Could be you are right:

http://www.x3mhc.no/dokumenter/SE-v-PP-Part1.pdf

But then, what's the fuzz about sticking to flea power in SET's if you could just increase the number of output tubes in parallel? What are the unavoidable tradeoffs?

I wonder ...