Dennis Had Inspire Amps

[BearCityUSA]

Originally Posted by FloridaBoy

Just get a pair of the EML solid plates and .

Why not mesh plates. The pair will cost almost as much as the amp.

[Bombadil]

While KT150s can result in more power in amps specifically designed for them for maximum output power, I haven't seen anything from Dennis to suggest that is true when using them in one of his amps. He told me that my amp will produce 17 wpc when using KT88, KT120, or KT150.

Has anyone seen any claims by him for more output power when using KT150s in one of his newer designs?

[decooney]

Originally Posted by Bombadil

While KT150s can result in more power in amps specifically designed for them for maximum output power, I haven't seen anything from Dennis to suggest that is true when using them in one of his amps. He told me that my amp will produce 17 wpc when using KT88, KT120, or KT150.

Has anyone seen any claims by him for more output power when using KT150s in one of his newer designs?

12wpc was the max I’ve ever seen hand documented by Dennis or for other Hot Rod amp references online. I actually like the SOUND of the KT150s in the Hot Rod in combo with my SLP-98 preamp using 50s Sylvania tubes.

[Bombadil]

He didn't make many of the 17 watt'ers. I suspect he sacrificed a bit of "Single-ended goodness" on the altar of deriving more power. There certainly is no triode mode available. Here is the text of his description of my amp when he listed it on eBay:

"FIRE-BOTTLE"
NEW HIGHER POWER
17 WATT PER CHANNEL
SINGLE-ENDED STEREO AMPLIFIER
KT-88/6550 TUBE
SINGLE-ENDED CLASS A

SPECIAL EDITION

"LATEST HO EDITION"

INSPIRE TUBE AMPLIFIER by DENNIS HAD FEATURING THE KT-88/6550 BEAM POWER VACCUM TUBE AMPLIFIER IN A SINGLE-ENDED CLASS A 17 WATT DESIGN

"INSPIRE FIRE-BOTTLE"

CLASS A, 17 WATT SE
KT-88 GENALEX OUTPUT TUBES
6SN7 INPUT DRIVER
5AR4, GZ-34 RECTIFIER TUBE
REGULATED OUTPUT KT-88 SCREEN GRID B+ VOLTAGE
REGULATED DC, B+ VOLTAGE ON DRIVER TUBE
REGULATED DC POSITIVE CATHODE BIAS ON DRIVER TUBE

INDIVIDUAL FILAMENT TRANSFORMERS FOR EACH OUTPUT TUBE

CUSTOM DESIGNED AIR-GAP 20 WATT OUTPUT TRANSFORMERS TO MATCH KT-88 TUBES AT FULL BANDWIDTH

I have designed and built in just about every special part but the kitchen sink in this new high output SE amplifier

Every Inspire amplifier and preamplifier is a new cool thing that never existed before today. I just love designing, building and sharing these single-ended class "A" amplifiers with music lovers in all corners of the world. After all these years I just love it!!!!!!!

This afternoon I am offering a special version of the original Fire-Bottle, powerful single-ended class A amplifier featuring the famous KT-88, 6550 output tubes. I gotta tell ya, the sonic presentation delivered by this amplifier will revitalize your musical enjoyment. You'll be listening to your record/music collection as if you were hearing the performers for the first time. This jewell delivers the emotion of the music ... big time. The amp plays like a 50 watter with amazing control and slam. I consider this a "life-time" amplifier.

If you have ever wondered about this single-ended vacuum tube audio craze ..... now is the time for an Inspire "Fire-Bottle" SE amplifier in your home listening room. No matter the choice of music you enjoy or the playback equipment you use, this affordable Inspire will reward the listener with the emotional impact and realism of the original score.

Thank you for your interest in the Inspire KT-88 HIGH POWER SPECIAL EDITION FIRE-BOTTLE offering and have a great day .........

Dennis J. Had W4USR Radioman731
retired Founder and President of Cary Audio Design

[decooney]

Speaking of "tubes" and "watts" and "sound", a response from Dennis about similar questions I had. It helped me to understand better, hope it helps others.

----------------------------------------------------------------------------------------

Good evening. I will compile a tube chart in a few days. I am running the Fire-Bottle monos in the pure class A triode SET mode. I am running 6550’s at the moment in a pair in my home at 15 watts per channel with 5U4 rectification. In the prototype stage I had these guys in the SEP pentode mode at 25 watts per mono. Give me a few days to get back to the mighty Fire-Bottle PSE monos and I will have a tube chart. I might mention that the mono’s running with a pair of 6F6G’s at 6 watts sound like a giant power house of SET power. It all boils down to driver control. I need to balance versatility and driver control to total power output. The first set of mono prototypes from a few months ago I was using a very low primary impedance output transformer for max power output. 19 watts triode with KT-150 PSE each mono but the sonic presentation was in your face … not a rich tube sound .. sounded more like solid state … so it takes a delicate balance. The sonic improvement with KT150 in PSE with the present transformers at 15 watts is smooth and controls the drivers well. Anyway ….. a few more days and more info. 5-15 watts will probably be the good balance for all tube rolling.Thank so much for continuing interest and I’ll talk to you soon. Dennis

----------------------------------------------------------------------------------------------

"In progress" as I understand it better now.

.
.

[Bombadil]

Oh there is no doubt that he has really dialed down how hard he is driving the tubes in his new mono amps. 15 watts out of two KT150s per channel is driving them easy. That's less than what a single KT88 produces in my amp. One could probably get 35 out of them when driven hard in SEP mode. I've read of people getting around 200 wpc out of two KT150s per channel in ultralinear PP mode.

[Breakdown7]

Enjoying reading about this...thanks for posting Dennis' words. I always like when he shares some info and it's passed on.

Anyone happen to have a wattage/output tube chart for the single chassis PSE pentode amp with IIPS? Ever since I've had the PSE amp, I've always ran either 6550's or KT88's. Not sure what tubes Dennis used and had in mind when building this circuit. Wondering what KT150's or EL34's would do in this amp.

I've bought a lot of stuff new directly from Dennis over the years, but not my PSE amplifier. So I never received the full info on it from an eBay listing. It's one of my favorite amps Dennis has produced to date. It seems to be very versatile with a variety of speakers. I use it with Green Mountain Audio Chroma HX speakers. 90db efficient with 4ohm impedance. The IIPS PSE amp wired in Pentode sounds wonderful with them!

[decooney]

Originally Posted by Breakdown7

Enjoying reading about this...thanks for posting Dennis' words. I always like when he shares some info and it's passed on.

Sure thing. It helps when analyzing "words" to understand better what is actually taking place. Corresponding over email or forums or eBay messages is not always easy - particularly as small preferences by each individual come into picture with a universal approach. I may check back later in a few months or after the first of the year to see how it goes once a little more gets worked out.

.
.

[BearCityUSA]

Originally Posted by decooney

Speaking of "tubes" and "watts" and "sound", a response from Dennis about similar questions I had. It helped me to understand better, hope it helps others.

----------------------------------------------------------------------------------------

Good evening. I will compile a tube chart in a few days. I am running the Fire-Bottle monos in the pure class A triode SET mode. I am running 6550’s at the moment in a pair in my home at 15 watts per channel with 5U4 rectification. In the prototype stage I had these guys in the SEP pentode mode at 25 watts per mono. Give me a few days to get back to the mighty Fire-Bottle PSE monos and I will have a tube chart. I might mention that the mono’s running with a pair of 6F6G’s at 6 watts sound like a giant power house of SET power. It all boils down to driver control. I need to balance versatility and driver control to total power output. The first set of mono prototypes from a few months ago I was using a very low primary impedance output transformer for max power output. 19 watts triode with KT-150 PSE each mono but the sonic presentation was in your face … not a rich tube sound .. sounded more like solid state … so it takes a delicate balance. The sonic improvement with KT150 in PSE with the present transformers at 15 watts is smooth and controls the drivers well. Anyway ….. a few more days and more info. 5-15 watts will probably be the good balance for all tube rolling.Thank so much for continuing interest and I’ll talk to you soon. Dennis

----------------------------------------------------------------------------------------------

"In progress" as I understand it better now.

.
.

This just in:



PSE Universal Monos + KT 150s = 14 watts






.
IMG_0964.jpg

[Bombadil]

14 watts out of two KT-150s per channel. That is really running them easy. The KT150s should last a fairly long time at that output.

Just today I came across a description of a KT150 single-ended amp, but running them in pentode ultralinear mode. He claimed 24 watts using just one KT150 per channel.