AudioAficionado.org - Dennis Had Inspire Amps

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- Inspire by Dennis Had (https://www.audioaficionado.org/forumdisplay.php?f=184)

- - Dennis Had Inspire Amps (https://www.audioaficionado.org/showthread.php?t=24170)

Quote:

Originally Posted by Bombadil (Post 1001144)

Looking at his currently posted for sale amps. They are described as SE Pentode (SEP) designs. And their output is 10 wpc.

As mine is rated at 17 wpc, it would seem that it would have to be SE Ultralinear. At least that's how I see it.

As memory serves, that sounds like a HO unit D made a few of way back when. Asymmetrical layout? Maybe an 1 1/2” lam stack on the opts? Did Florida Boy have/had one from the same run? What you say FB? Sound familiar?

Quote:

Originally Posted by bearcity (Post 1001154)

Yes, that is what it is. An HO, High Output, design. Large 20 watt output transformers.

I haven't seen him advertise one for a long time. Probably not his favorite design. Mine was built in May, 2016. I purchased it in July, 2016.

From his old ad 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

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

I very much like my HO amp. It sounds great and drives my 91dB speakers to loud levels with strong, solid bass, while still retaining much of the tube "goodness." From what I've read about it, I suspect I would like the PSE amp even better, where the tubes are not driven quite so hard and with the new voltage regulation. That said, the HO does make me happy.

I believe that different types of tubes are affected by the HO design in ways which make the listening experience different with this amp as opposed to triode-design 8 to 10 watt models. The high output tubes, KT88/120/150, sound very natural and powerful. Not surprising given that the amp was optimized for these tubes. While some of the low output tubes sound more stressed, and can be outright unenjoyable.

Quote:

Originally Posted by bearcity (Post 1001154)

Nope, mine is triode strapped and built with the larger transformers.

Quote:

Originally Posted by Bombadil (Post 1001172)

I very much like my HO amp. It sounds great and drives my 91dB speakers to loud levels with strong, solid bass, while still retaining much of the tube "goodness." From what I've read about it, I suspect I would like the PSE amp even better, where the tubes are not driven quite so hard and with the new voltage regulation. That said, the HO does make me happy.

I believe that different types of tubes are affected by the HO design in ways which make the listening experience different with this amp as opposed to triode-design 8 to 10 watt models. The high output tubes, KT88/120/150, sound very natural and powerful. Not surprising given that the amp was optimized for these tubes. While some of the low output tubes sound more stressed, and can be outright unenjoyable.

There is a PSE with IIPS for sale on USA Audio Mart. I bought Beatlebums PSE with IIPS about a year ago and it's a keeper for me.

Quote:

Originally Posted by oldominion (Post 1001007)

So funny, in my Inspire Firebottle Universal SET I just swapped out my KT150's and Sophia 274B for Haltron 6V6 and a Sylvania VT244 (5u4G) and it sounds absolutely wonderful!

Might have to try the el84's. I've never cottoned to that tube like so many others in our hobby have. In fact, I've sold every el84 amp I've ever purchased, and somewhat quickly. I love it as a guitar amp tube but, again, have never really fallen in love with it as a hifi/audio tube. Still, I have a bunch of el84's that are gathering dust, including a quad of Mullards, so may have to give it a shot...

I was convinced I'd never take the KT150's/274B out but, as happens during the quarantine, was procrastinating and avoiding work so decided to mix things up. Man, am glad I did. On mellower stuff--listening to Brazilian Gal Costa right now--there is a smoothness, subtleness and, dare I say it, delicacy to the presentation that I guess I was sort of missing with the 150's.

ANyhow, good advice: keep as many tubes on hand as you can!

Would love to hear anyone's thoughts about 6V6 vs. 6L6. I have some of the metal ones and the cheap Russians that Dennis recommended me.

BTW, the Sophia 6SN7's are definitely settling down. Thus far, I like them but am pretty sure I've got plenty of vintage 6SN7 that sound just as good. They do appear to be stable--I'm not having much microphony UNLESS I touch the tubes while playing, which thankfully I don't often do!

I like the old 6L6G/GA tubes and 6V6's in my PSE. However, tube preference is not universal and depends on the rest of your system. You have to experiment

Methinks your Sophia Blues are still settling in.

Did you try the Sophia 274B with the Haltrons?

Sometimes I wish my amp could run just two or three types of output tubes.

Presently in my tube box lie
EL84 - 6 pair
6V6 - 4 pair
5881 - 2 pair
6P3S-e - 2 pair
6L6GC - 2 pair
KT66 - 1 pair
EL34 - 1 pair
6CA7 - 4 pair
KT77 - 2 pair
KT88 - 3 pair
KT120 - 1 pair
KT150 - 1 pair

And I still find myself perusing ads for some different 6L6s, EL34s, and KT90s.

I do have two other EL34/KT77 amps and two EL84 amps. But most of the above tubes take rotations in my Inspire.

I'm not even going to mention my boxes of 6SN7s and various rectifiers.

Quote:

Originally Posted by FloridaBoy (Post 1001223)

Do tell more about the Blue Sophia 6SN7's. Do they do anything that the good NOS tubes don't do? Just saw these when I came across the Blue KT88's.

Quote:

Originally Posted by PSE45 (Post 1001313)

Do tell more about the Blue Sophia 6SN7's. Do they do anything that the good NOS tubes don't do? Just saw these when I came across the Blue KT88's.

I tried one in my LP27a and found the reviews to be spot on. It performed better in my rig than any of the old production tubes I have. It did take a good while to settle in. YMMV.

Quote:

Originally Posted by FloridaBoy (Post 1001371)

I tried one in my LP27a and found the reviews to be spot on. It performed better in my rig than any of the old production tubes I have. It did take a good while to settle in. YMMV.

They must have a lot of variation in their tubes as it pertains to audio quality.
I owned their 274b mesh rectifier, worst rectifier I've ever tried (and if anybody owns one here, it's just a imo ymmv)

I also tried their "premium" 6sn7 (gold base, their cheaper 6sn7 versus the blue glass y'all are talking about). Again, one of the worst 6sn7 I've tried.

Reviews for their 300b/2a3 mesh always come in as bottom tier, much worse than cheaper JJ 2a3/300b.

With that said, I've read rave reviews about their extremely expensive Royal Princess 300b. I might have to pick up the blue 6sn7 to try, you guys really seem to like it. I just never touched Sophia again after my earlier experiences with them.