Dennis Had Inspire Amps

[BearCityUSA]

Originally Posted by Formerly YB-2

BearCityUSA - That is a very neat build on your KT. What four (4) tubes does it use? Do wish Dennis had a website that listed his offerings. As far as UL, my SLI-80, a many years old Dennis design, sounds much better to my ears in Triode as opposed to UL (switch selectable).

As fr tubes in my KT, 2013 vintage.
5 volt rectifier, I find it ootput tube specific for best sound
9pin driver, favorites are bugle boy 6dj8 and 6n6p (12bh7 with 6cg7 pin out)
Octal beam pentode output tubes, 6v6gt (popes) and jj kt-77s are some of my faves but I like 6l6 as well. Not such a fan of kt-88 or kt150.

Your experience with the SLI-80 is the same as I had with my CAD-50 mk2. Best sound in triode mode, not in UL. Of course it was PP and in no way sounded as good as either on my Inspire SEP amps.

[BearCityUSA]

Originally Posted by pstrisik

Regarding the Ultralinear question, Dennis emailed the following to me back in 2014 (posted with his permission):

Thanks Peter. That clears things up. I can go about life as I have for 15 years now, believing I am not interested in UL circuits.

[Analog Addict]

Originally Posted by FloridaBoy

They are good tubes. tubeman.com, a good vendor, had some that were cryo treated. There is a nice pair of RCA's on the auction site for $29 buy it now.

Bear, *I* would not chase 'rare' old production power tubes. Like TS 6550's The pickings are slim and new production has eclipsed them. I have the new production TS 6550 and it is a great tube. So is the Shuguang 6550. YMMV.

Email just in from Dennis....

Allan:
Your 6550’s are heating up the room!!!! Man-o-man do they sound good.
Dennis

Originally Posted by BearCityUSA

Thanks Peter. That clears things up. I can go about life as I have for 15 years now, believing I am not interested in UL circuits.

Allan:

Let BearCityUSA know that his amp is in the pentode class a mode. No stinkin ultra-linear, degenerative feedback for his ears!!!!

Dennis

[Formerly YB-2]

Anyone know what speakers is Dennis using these days?

[BearCityUSA]

Originally Posted by Formerly YB-2

Anyone know what speakers is Dennis using these days?

Dennis is a bit of a speaker collector. Well maybe not a collector but he does seem to like to give many a try. Last I was at his Toy Factory there were 2 pair in/near to listening position. There were the Inspire open baffles which he designed with Allen (Analog Addict) which I auditioned while there. See previous post. The other pair is the taller 5 ways (4 open baffle drivers, 3 front facing, 1 rear and a 15" woofer in a sealed box at the bottom) designed by DH which show up in many of his videos. I recall hime leaning on them in interviews. Both have that distinct OB sound and do have a good synergy with the Inspire components. Strewn around the room were several other pair. Some nicer than others. I recall a pair of narrow floor standers with a tweeter horn sculpted from a thick (maybe 4") stack of thin layered plywood. If memory serves they were German and Dennis said they sounded great. Also present were a pair of monitors which he said he got for $60 new. Looked like some of the cheapest you might ever find at the Shack. He said they sounded terrible. We both laughed. I have not been to his house but I think he mentioned some very nice Vanderstiens. Don't recall the model but I do recall mention of a >$10K retail. Later he also told a story of an impulse Polk buy which had amazed him. Early impressions were that they gave the Vandys a challenge at <25x the price. Again laughter.

Others local to Cary i am sure could tell more. He is fun to talk about such things. I wish i had some experience with ham radio so as to have more in common.

[Analog Addict]

Originally Posted by BearCityUSA

Dennis is a bit of a speaker collector. Well maybe not a collector but he does seem to like to give many a try. Last I was at his Toy Factory there were 2 pair in/near to listening position. There were the Inspire open baffles which he designed with Allen (Analog Addict) which I auditioned while there. See previous post.

Here's the lineup. These speakers were created specifically for the Inspire line up of tube gear, and although they will sound great with other sources, really shine with Dennis' other products....

Originally Posted by BearCityUSA

The other pair is the taller 5 ways (4 open baffle drivers, 3 front facing, 1 rear and a 15" woofer in a sealed box at the bottom) designed by DH which show up in many of his videos. I recall hime leaning on them in interviews .

Here is the aforementioned pair. I was not involved with this set of speakers, but they are also very nice sounding.

Originally Posted by BearCityUSA

Both have that distinct OB sound and do have a good synergy with the Inspire components. Strewn around the room were several other pair. Some nicer than others. I recall a pair of narrow floor standers with a tweeter horn sculpted from a thick (maybe 4") stack of thin layered plywood. If memory serves they were German and Dennis said they sounded great. Also present were a pair of monitors which he said he got for $60 new. Looked like some of the cheapest you might ever find at the Shack. He said they sounded terrible. We both laughed.

I'm an Altec collector and DIY fiddler. Here's a set of prototype OB speakers using a set of Altec 604-8G's out of a Urei 813. Note the distinctive UREI manta ray horn.



These are currently hiding in the corners of Dennis shop listening room. Altec components in a Electrovoice Aristocrat enclosure with Dennis' custom crossover. Amazing sounding speakers, like mini Model 19s....

Originally Posted by BearCityUSA

I have not been to his house but I think he mentioned some very nice Vanderstiens. Don't recall the model but I do recall mention of a >$10K retail. Later he also told a story of an impulse Polk buy which had amazed him. Early impressions were that they gave the Vandys a challenge at <25x the price. Again laughter.

Dennis has a pair of very expensive Tannoy single driver speakers at home. here they are pictured with that cheap set of Polks. believe it or not, the Polks sounded really nice for a fraction of the cost....

Originally Posted by BearCityUSA

Others local to Cary i am sure could tell more. He is fun to talk about such things. I wish i had some experience with ham radio so as to have more in common.

[Formerly YB-2]

Originally Posted by Analog Addict

Here's the lineup. These speakers were created specifically for the Inspire line up of tube gear, and although they will sound great with other sources, really shine with Dennis' other products....

Can't get that first picture of the Inspire speakers to come up again. Who makes these speakers? Any chance of getting a picture of the back?

[Rosco65]

Thanks so much Allen. I recall seeing some of these pictures before. A number of interesting points arise:

1. High efficiency open baffle speakers have a lot going for them. The old Siemens Klangfilm Bionor speakers were huge OB/horn speakers. There are lot of people are coming around to open baffles, but they do require an appropriate room to work.

2. I like seeing what looks like a 4" cone "tweeter" in Dennis OB three way. I have some Omega speakers with 4.5" drivers that do an honest 17khz or 20khz at 94-95dB/w/m. These drivers can be crossed over at virtually any frequency (or none at all).

3. I'm also a fan of vintage Altec speakers. One of my systems comprises an Altec 414A in a 614 cabinet with an 802D on a 32A horn with custom crossovers. This is an honest 99dB/w/m system that doesn't take up too much room and gives solid in-room response to 40hz. The Altec 414A is one of the best midrange drivers ever made. It needs no crossover at all and can run full range from 40-4,000 hz (at 99dB!). You sacrifice the bottom octave of bass, but that is a small price to pay.

[Musica Amantem]

Quote from Analog Addict: "Dennis has a pair of very expensive Tannoy single driver speakers at home. here they are pictured with that cheap set of Polks. believe it or not, the Polks sounded really nice for a fraction of the cost...."

In that image (which I chose not to reproduce here again for efficiency's sake) it is quite evident there are no room conditioning devices, except for the floor carpet. This, even with glassy windows on two sides of the room ... Interesting!

[x3workshop]

Originally Posted by Musica Amantem

Quote from Analog Addict: "Dennis has a pair of very expensive Tannoy single driver speakers at home. here they are pictured with that cheap set of Polks. believe it or not, the Polks sounded really nice for a fraction of the cost...."

In that image (which I chose not to reproduce here again for efficiency's sake) it is quite evident there are no room conditioning devices, except for the floor carpet. This, even with glassy windows on two sides of the room ... Interesting!

I think everyone listens differently. I don't mean that we all 'hear' differently, that's a given, but that our listening criteria are vastly different.

I'm assuming that you're commenting on the fact that Dennis's listening space isn't super carefully thought out since his life has been about music reproduction? Maybe it is and that's the beauty of the Inspire gear. It's made to enhance the experience in almost any space. Of course treatments and speaker placement improve the acoustics. No question.

I know you are a very critical listener who, from what I surmise from your posts, prefers absolute accuracy and balance of reproduction with the least bit of interference from a room. *Please correct me if I am mistaken.*

I think it is genre dependent as well. An opera or classical listener will have different criteria than a Folk, Jazz, or Rock listener will. I don't know what Dennis's tastes are, so I can't comment.

Curious to hear other's thoughts as well.