Dennis Had Inspire Amps

[pstrisik]

Hi SteveSem..... welcome to the thread!

Which amp did you get? The link to the photo isn't working for me.

[SteveSem]

Originally Posted by pstrisik

Hi SteveSem..... welcome to the thread!

Which amp did you get? The link to the photo isn't working for me.

Hi Peter,
Well, that's an interesting question. I tried to post the photo another way in a second post that also contains my question about amp types. That post is still waiting review. They guy who I purchased the amp from said he asked Dennis to make "his favorite amp" and Dennis chose the 6L6. But the amp came with the KT88 tube, which the first owner loved and never changed, even though Dennis provided 3 sets of tubes with the amp. So, I guess that the answer is 6L6. But I am trying to figure out what that means given that the amp also use KT88's or KT77's. I am sure it is just my ignorance that is confusing me?!?

[jdandy]

SteveSem.......Welcome to Audio Aficionado.

[BearCityUSA]

Originally Posted by SteveSem

OK, my first attempt to post the link to a picture did not work. So, now I'm trying it another way: Here And here is my first question, which I'm sure is quite basic. But I am brand new to the tube amplifier world. I understand that the Inspire amps are all single ended SET or SEP amps. I'm trying to understand what the name designations mean. Although mine doesn't say it anywhere on the amp, I understand that Dennis identified it as a 6L6 amp. Yet, it can use KT77 and KT88 tubes. I've searched the forum and found instances where guys refer to their amps as 6L6, various KT's, and 45s. But no one seems to have explained what this designations convey given that the amps all seem capable of using a variety of tube types. Many thanks in advance. Steve

Great question. I have often wondered where the tech differences are between the Inspire lines of amps. The chassis have varied over the years. I have one of the biggest in my KT66/88/120 from 2013 that I have seen. (I will get Picts on here one day, I promise). Some later Fire Bottles are mid sized and his recent IFA 's are petite. Each seem to come with differing faceplates and tube compliments. From this thread I have also wondered what the internal differences are since my conclusion from this thread is also 'any beam powered triode will due as long as you match the rectifier appropriately'. Not sure if this rule of thumb goes for the 45s. They seem more unique. Ultimately I have to claim the same ignorance as you. I wonder if this is a question Dennis is willing to answer. I do not know him well enough to ask.

[pstrisik]

Originally Posted by FloridaBoy

I have read that Mullard 807's are not 'winners'. I am going to check out some RCA 6BG6G's and will post. *I* think how and where these types of tubes were stored over the years can be an issue. I posted earlier about some NU 6BG6's. I got them from a good seller but he was not able to try them in an amp. They tested great but were unusable.

I just yesterday received the Visseaux 6K6GT's and a Brimar 5Z4GY to go with them. First listen last night was surprisingly good. We'll see if this combo is up there too after a few days and then returning to the old standbys to compare.

Peter, with the lights out in the room do you notice and red plating of the 6K6?

No red plating - I assume you mean something inside the tube glowing that shouldn't.

Are you using the 5Z4GY rectifier? You had said something about using that one as the others were stronger in some way.

[pstrisik]

Originally Posted by SteveSem

Hi Peter,
Well, that's an interesting question. I tried to post the photo another way in a second post that also contains my question about amp types. That post is still waiting review. They guy who I purchased the amp from said he asked Dennis to make "his favorite amp" and Dennis chose the 6L6. But the amp came with the KT88 tube, which the first owner loved and never changed, even though Dennis provided 3 sets of tubes with the amp. So, I guess that the answer is 6L6. But I am trying to figure out what that means given that the amp also use KT88's or KT77's. I am sure it is just my ignorance that is confusing me?!?

Somethings remain a bit of a mystery. Dennis constantly changes his designs and doesn't seem to want to get into specs or technical detail. He's readily answered when I've had a problem though or even a specific question.

My sense about the range of SEP amps he's done is that the differences in design are subtle. I know there are transformer differences. He said, for example, that my KT-150 had heavier duty transformers since he designed it for that higher power tube. I think he has since upped his transformer level in general though.

This range all run a large variety of pentodes: 6V6, 6K6, EL-34, EL-37 KT-66,77,88,120, 6550, on and on. His designs seem to be bullet proof. No damage if speakers aren't connected, tolerates all sorts of tube combinations, etc.

The wide range of tubes that are possible make these amps quite fun and customizable with tube rolling. That can also be a curse since you will never run out of different tubes to try!

[FloridaBoy]

Originally Posted by SteveSem

OK, my first attempt to post the link to a picture did not work. So, now I'm trying it another way: Here

And here is my first question, which I'm sure is quite basic. But I am brand new to the tube amplifier world. I understand that the Inspire amps are all single ended SET or SEP amps. I'm trying to understand what the name designations mean. Although mine doesn't say it anywhere on the amp, I understand that Dennis identified it as a 6L6 amp. Yet, it can use KT77 and KT88 tubes. I've searched the forum and found instances where guys refer to their amps as 6L6, various KT's, and 45s. But no one seems to have explained what this designations convey given that the amps all seem capable of using a variety of tube types.

Many thanks in advance. Steve

Welcome Pilgrim,

I saw your amp on the auction site. They are single ended amps that can use pentode and tetrode tubes. I saw your amp on the auction site it included a good selection of power tubes. *I* would not buy anymore until you are familiar with what you received.

Do you have it now?

What speakers will you be using?

What are you going to use as a preamp?

Which rectifier came with the package? This is where you may want to experiment. They have a large bearing on the sound.

Print out the 5 volt rectifiers on this link. It will be a good reference.

http://www.fourwater.com/files/fullrect.txt

[FloridaBoy]

Originally Posted by pstrisik

Somethings remain a bit of a mystery. Dennis constantly changes his designs and doesn't seem to want to get into specs or technical detail. He's readily answered when I've had a problem though or even a specific question.

My sense about the range of SEP amps he's done is that the differences in design are subtle. I know there are transformer differences. He said, for example, that my KT-150 had heavier duty transformers since he designed it for that higher power tube. I think he has since upped his transformer level in general though.

This range all run a large variety of pentodes: 6V6, 6K6, EL-34, EL-37 KT-66,77,88,120, 6550, on and on. His designs seem to be bullet proof. No damage if speakers aren't connected, tolerates all sorts of tube combinations, etc.

The wide range of tubes that are possible make these amps quite fun and customizable with tube rolling. That can also be a curse since you will never run out of different tubes to try!

That is the main difference. My amp was built on the 45 amp layout with 20 watt transformers and a UX-4 rectifier socket. In most other ways they are very similar.

However, Dennis did build one with a switch for 3 bias points, EL34, 6L6, and KT88's.

[SteveSem]

Thanks pstrisik and FloridaBoy. I appreciate the link to the rectifier tubes. I admit that a big attraction to these amps was that each had its own character imparted by someone with a long track record and a continuing love for what he's doing. The story behind my amp is that Chip contacted Dennis in December 2014. He basically said "make me your favorite amp, but make it a little special." It came in the copper color with no name plate -- just the Inspire logo on the front -- things that were probably special in January 2015, but have surely been repeated on many amps since then. The inscription on the bottom does not refer to a tube number. Just "Firebottle." But Chip said that Dennis told him that it was a 6L6 amp. And as FloridaBoy wrote, one of the "make it special" things that Dennis did was to provide 3 full sets of tubes that would show off the range of the amp. According to Chip, though, he liked the KT-88's and never tried the others. I don't have the amp yet. It should arrive in the next couple of days. I'll provide some info on my system as well as the specific tubes in a future post. Here and Here are links to a picture with the tubes loaded and the inscription.

[pstrisik]

Originally Posted by FloridaBoy

That is the main difference. My amp was built on the 45 amp layout with 20 watt transformers and a UX-4 rectifier socket. In most other ways.

However, Dennis did build one with a switch for 3 bias points, EL34, 6L6, and KT88's.

He's also made one with a switch for triode/UL mode (I think UL - are ours UL?).