Inspire audio equipment

Tubefly · « **Reply #80 on:** 1 Apr 2021, 09:52 pm »

Quote from: straitwire on 22 Sep 2020, 01:34 am

Hello everyone, I build Inspire audio equipment.

Hello Straitwire, I am hoping you can assist me with a tube rolling guide for Fire Bottle SE Stereo Tube Amplifier HO with the IPS upgrade. I recently bought the amp used, and well love it. My only complaint is no tube rolling guide. Thank you in advance, and for building such great gear.

My Best, Alan

FullRangeMan · « **Reply #81 on:** 1 Apr 2021, 10:04 pm »

Quote from: Tubefly on 1 Apr 2021, 09:52 pm

Hello Straitwire, I am hoping you can assist me with a tube rolling guide for Fire Bottle SE Stereo Tube Amplifier HO with the IPS upgrade. I recently bought the amp used, and well love it. My only complaint is no tube rolling guide. Thank you in advance, and for building such great gear.

My Best, Alan

See post 46 or Dennis ad at Ebay.

straitwire · « **Reply #82 on:** 1 Apr 2021, 10:51 pm »

Hey Alan, because your amp has an IIPS (Infinite Impedance Power Supply) you can run a 5Y3 a 5U4 or a 5AR4 rectifier or their equivalents because the high voltage (B+) on the output tube plates doesn't change regardless of which rectifier you use.
The B+ on the input tube plates is regulated so it doesn't change either.

The output tubes you can use are.
6F6
6V6
6L6
V350B
EL34
5881
6CA7
KT66
KT77
KT88
6550
KT90
KT120
KT150
KT170

The input tubes you can use are.
6SN7
6SL7
6BX7
CV181

Let me know if you have any other questions.

Tom Bombadil · « **Reply #83 on:** 2 Apr 2021, 12:17 am »

I believe Straitwire meant 6CA7 not 6CA4 above.

You can also use 7581a output tubes, these are upgraded 6L6GC.

I've even used EL84 in my Inspire amps, but it requires an EL84 to 6V6 adapter.

You could also use Russian 6H8C/6N8S (equivalent to 6SN7) or 6H9C/6N9S (6SL7).

straitwire · « **Reply #84 on:** 2 Apr 2021, 01:59 am »

Hey Tubefly, I'm running some KT170's and they're really nice.

Here's some pics of the new 300B amp.

Sonicjoy · « **Reply #85 on:** 2 Apr 2021, 03:02 am »

I must say I agree Straitwire. The KT-170's are sounding wonderful in the SE HO. Very nice deep bass, and clean, detailed and smooth.

Opus Flatus · « **Reply #86 on:** 13 Apr 2021, 06:10 pm »

You gents have convinced me to buy a pair of KT-170's. I'm currently using the KT-120's in my SET Universal, which I like a lot. Hopefully, these tubes will not be as unreliable as some of the early production KT 150s were.

Sonicjoy · « **Reply #87 on:** 13 Apr 2021, 07:22 pm »

Well so far so good, I'm around 400 hours. Very happy thus far! Just enjoying the music!

Opus Flatus · « **Reply #88 on:** 13 Apr 2021, 09:50 pm »

That's good to hear. I can't wait to fire them up.

Opus Flatus · « **Reply #89 on:** 16 Apr 2021, 01:39 am »

The KT 170's have arrived! Everything about this tube is big...big size, big clean bass, big deep soundstage, and big on detail/imaging. Loving it so far and the tube isn't broken in yet. This is my favorite output tube in my Inspire so far.

Sonicjoy · « **Reply #90 on:** 17 Apr 2021, 12:34 am »

Again I concur. They seem to do everything well. Glad you like them!

straitwire · « **Reply #91 on:** 1 May 2021, 08:36 pm »

Working on a phono preamp.
Built a prototype on an LP-3 chassis and put in some voltage regulator tubes for the heck of it.
The production prototype chassis is smaller and configured differently without using VR tubes.

Sonicjoy · « **Reply #92 on:** 1 May 2021, 09:11 pm »

Very cool! I have been looking at the Decware ZP3 phono amp but would really like a matching Inspire phono stage.

BearCityUSA · « **Reply #93 on:** 5 May 2021, 11:41 am »

A post I may published elsewhere:

I made a trip East from Asheville, NC this past week and of course stopped by Cary for a visit with Dennis and Tony (Straitwire). Allen (Analog Addict) could not make it.☹️ As usual we caught up over lunch and then off for some critical listening, sharing of ideas, and also what has become a real treat, story time. I brought my latest speaker project, a single driver rear loaded horn. Pictures to follow. System components included the shop Rega P3 turntable> Assorted phono-preamps> Inspire CJ5 preamp (prototype)> The new Inspire 300b amp and a new Inspire KT88 SETamp (to be shipped on Monday to a customer). Speakers were various prototypes of the the speakers I brought which we have all been playing with.

My interests going in were to give the KT170s a listen. I knew Dennis had a pair. I also wanted to hear the new 300b amp with those new production Western Electric 300b tubes. I also wanted Dennis and Tony to hear my latest speakers. IMO, at present, these are the best yet from my shop. We hooked up the speakers before we went to lunch so they would be all warmed up when we got back. We had to wheel the shop 4 ways out and the pair with the Lii f15 drivers I made for Dennis a while back so as to make room to move around. There is a lot of equipment there at the toy factory, often just out of view of the pictures shown here.

Listening began with the 300b. WOW what a presentation. The best way I can convey the experience: remember the first time you heard a good SE setup? That feeling of realization regrading all you have been missing previously in your audio system listening life. Well damn if Dennis did not do it again with this one. There is no doubt that this amp bests his other offerings of which I own several. His SEP Firebottle amps are currently running about $2k (maybe the best bargain in hi-fi) and this 300b is $4k so it should, and it does in spades! As I sit here now listening to it in my listening room (yes, I took it home with me) I am just floored by the detail, fluidity, and timbre. The instrument separation is unmatched. Absolutely amazing presentation.

We switched to the KT88 SET (triode) amp next with the KT170s. BTW, same OPTs in both amps I was told. I will preface this with this statement. I have yet to meet a pair of KT 88/120/150s I cared for. I know there are many out there who love this class of tube but I always seem to prefer the 6f/l/v6 Pentodes. The KT 170s are the same for me. I switched them out for a pair of 6f6g from the mishmash of tubes there on the coffee table. There was the sound I know so well and absolutely love from my other Inspire amps (custom Universal, PSE, and 6V6er). Wonderful! If the fellow who is having this amp shipped on Monday is here reading this. You are in for a real treat. This is a wonderful amplifier. But IMO, get yourself some 6f6s to try.

Listening was through the various cabinets and with various drivers (Fostex 4”). Dennis has been in love with the FE126NV for a while and we have each been playing with the FF125WK. No firm conclusions were made but I was coerced into leaving my latest cabinets. You’ll have that there at the toy factory. I am missing them a lot as I sit here.

After a lot of listening, laughing and sharing, we seem to find ourselves engrossed in Dennis’s stories of times past. We went strolling down memory lane with him and his before and after Dentron Radio days. Mid to late 70’s. He pulled up some youtube videos on his phone which brought up more stories. Maybe we can get a podcast together someday. The man has really seen and done a lot in his lifetime.

Anyway, I had to get on the road and they each had to get home to their families. Another great visit was over. As always I look forward to the next.

Opus Flatus · « **Reply #94 on:** 5 May 2021, 02:05 pm »

BearCity,

Thanks for the update on your recent visit to the "Toy Factory", sounds like an awesome experience. I am glad I stumbled across the Inspire amps a few years back. I love the fact that I can roll in a variety of tubes, the craftsmanship, and the engineering that goes into his labor of love. I Look forward to future updates.

Tyson · « **Reply #95 on:** 5 May 2021, 11:55 pm »

I have a pair of Inspire MB12 monoblocks from 2014 and I absolutely love them. They drive the top part of my GR Research Super 7 speakers better than any other amp I've heard. The Super 7's are a perfect match for them, with the planars covering 150hz to 20khz, 97db efficient and ruler flat 8 ohm impedance, and all bass is offloaded to a separate, self powered bass section.

In my setup the MB12's are simply exceptional.

straitwire · « **Reply #96 on:** 22 Jun 2021, 08:08 pm »

I'm almost done with the new phono preamp.
I ordered some caps for it, they should be here Thursday.
Once I complete it I'll give it to Dennis so he can finalize it.

straitwire · « **Reply #97 on:** 25 Jun 2021, 12:18 am »

Fired it up, sounds great!

FullRangeMan · « **Reply #98 on:** 25 Jun 2021, 10:01 am »

What I like in Dennis amps are he use the big tone 6SN7 octal

roscoe65 · « **Reply #99 on:** 20 Jul 2021, 03:23 am »

Quote from: straitwire on 9 Mar 2021, 01:56 pm

If you could post a picture of the inside of your amp I can tell you if it has an IIPS.
I change the circuit in my amp whenever Dennis comes out with a new mod or with an entirely new design which includes output transformers.
It has been several years since I ran an IIPS so I really can't comment on improved bass.

The Gas Voltage Regulated PSE uses 0A3 voltage regulator tubes instead of zener diodes to regulate the high voltage.
This gives a slightly lower noise floor because VR tubes are quieter than zener diodes.
Otherwise it's the same circuit as a PSE.

Hi Straightwire,

Can you elaborate on why you don’t run the IIPS?