Dennis Had Inspire Amps

[nhparrot]

Originally Posted by Oly84

Thanks for the reply. As a 6V6’er owner I am wondering if someone who knows their tube combinations would be willing to throw together a simple chart showing which rectifier and driver tubes can or should be used with a certain power tube pair. Currently running VT170’s with a 5AR4 and a 6SL7GT all TUNGSOL. Ready to try tube rolling but not sure what to pair up. Thanks in advance for any help you all can provide.

Output Tube - Rectifier Tube
6L6, 5881, or KT66 - 5AR4, 5U4, or 274B
6V6 - 5Y3, or 6106
6V6GT - 5U4, 274B, 5Y3, or 6106
EL34, 6CA7, or KT77 - 5AR4, 5U4, or 274B
6550, KT88, KT90, KT120, or KT150 - 5AR4, 5U4, or 274B

Input Tubes
6BX7 - Has a deeper sound stage with more weight in the lower mids.
6SN7 - Has more gain than the 6BX7 with lower midrange heft
6SL7 - Has more gain than the 6SN7 and sparkle in the top end

For my 6L6 Firebottle (SEP) built in January 2015 output was tested by Dennis as:
Output Tube - Power
6L6, 5881, or KT66 - 8 to 10 watts
6V6 - 6 to 8 watts
EL34, 6CA7, or KT77 - 8 to 10 watts
6550, KT88, KT90, KT120, or KT150 - 9 to 14 watts

[Bombadil]

Yesterday I decided to try a new setup. Not long ago I purchased a used PS Audio DirectStream DAC. This was on the Stereophile Recommended Class A list for years and is now better than ever with the software upgrade they released last summer. It has variable volume out, so I decided to connect it directly to my Inspire PSE.

The DirectStream has an Ethernet Bridge card in it, connected via wire to my router. I subscribe to Qobuz and selected some of their Hi-Res 24/192 songs.

Wow! It sounded like the bands were in my room. Huge, open soundstage. Instruments and voices sounded live, no hint of compression or boxiness. Norah Jones sounded like she was right there in the room. I could hear the strings on pianos vibrating with rich harmonies. The acoustic bass player was right over in the corner, every note distinct and well-defined.

Single-ended amps have always been known for their natural presentation and it was there in heaps and bounds. None of this "classic tube sound" which is generally thought of as being warm'ish with some mid-range bloom and maybe a bit of softness on highs. Just like when one listens to a violinist live, it has a bite to the sound, that "bite" was there. Drums were snapping. Saxophones blaring.

But there was no harshness to it. No glare. Lots of detail but not overly bright.

Didn't play around with my tubeset, had my standard set in there. My trusty Westinghouse 6SN7GTB, Tung-sol KT120 and a vintage RCA 5U4GB. Total price paid around $190. Cabling is nothing special - $40'ish Mogami interconnects, 25 year old Audioquest speaker cables, $10 Tripp-Lite power cables.

I use the Westinghouse because it is the most open, natural sounding 6SN7 I've run across. I've tried around 25 in all and it and a Raytheon VT-231 are my favorites. I own 5 of the Westinghouse, so I will never run out.

Speakers are my old trusty custom-modified (by the original designer) Von Schweikert towers. This model is long out of production but he told me a few years back that if he were making them now, they would cost $12K-$14K.

I've owned Inspire amps for nearly 7 years, this is the best I've ever heard from them. Awesome, simply awesome. Looking forward to listening to some other output tubes in the same setup.

[FloridaBoy]

Originally Posted by Bentan

I’m continents away to pay you a visit but I’d like to know what are your thoughts on these two amps too. Is the gain the same as the CJ5?

Sorry, I did not see this post. I don't know what the gain is for the CJ5.

[Oly84]

nhparrot
Thanks for the chart! Let the rolling commence!

[Oly84]

Bombadil, Could you elaborate on the Westinghouse 6sn7 you mentioned? Do you know the year, is it chrome top or tall boy etc.? Also. the Raytheon. Really don’t want to repeat your going through 25 different 6sn7’s, even though I know what sounds best to you in your system might not be the same in mine, but it should still be a great starting point. Have you or anyone had a chance to try the RCA red bases? Thanks all.

[CohibaJoeLuxman]

Installed KT170's into Firebottle KT88 Amp...After 15hrs the music is Cleaner, Deeper and has a Wider Soundstage. The KT88's (125hrs) are a "Jazz Club" sounding tube, very smooth and the sound is directly in front of you. Leaving the KT170's to put some Hrs. Hooked up to tubes4hifi SP14-V22 Pre-Amp and Zu Audio Dirty Weekend MK.II

[Masterlu]

CohibaJoeLuxman… Welcome to AA!

Your Subscriber Banner looks great!

[nhparrot]

Originally Posted by Oly84

Bombadil, Could you elaborate on the Westinghouse 6sn7 you mentioned? Do you know the year, is it chrome top or tall boy etc.? Also. the Raytheon. Really don’t want to repeat your going through 25 different 6sn7’s, even though I know what sounds best to you in your system might not be the same in mine, but it should still be a great starting point. Have you or anyone had a chance to try the RCA red bases? Thanks all.

I just replaced the driver tube in my Inspire amp with a CBS labelled 5692 red base.

[Bombadil]

Originally Posted by Oly84

Bombadil, Could you elaborate on the Westinghouse 6sn7 you mentioned? Do you know the year, is it chrome top or tall boy etc.? Also. the Raytheon. Really don’t want to repeat your going through 25 different 6sn7’s, even though I know what sounds best to you in your system might not be the same in mine, but it should still be a great starting point. Have you or anyone had a chance to try the RCA red bases? Thanks all.

The Westinghouse which I like was made by Westinghouse (not one of their relabeled issues) in the 1960s. It has yellow text, is taller than a normal 6SN7 and has a copper rod.

I do have a RCA red base 5692, which I find to be okay. It produces a smooth sound but without as much detail on higher frequencies. Sound stage is a bit diminished both in depth and width, not a lot but noticeable. In my setup this is not a favorite of mine, but maybe in a system/room which is a bit bright, this could be a nice pairing.

My 1940s Raytheon VT-231, with bottom getter, is very good. Open and transparent. Sounds very close to my Westinghouse, perhaps a shade better. I haven't decided on this as yet.

Also a Psvane CV181-T Mark II, another "smooth" sounding 6SN7, something like the RCA 5692 but a bit more open sounding in my system. I do occasionally use this one.

Along with many Sylvania, Hytron, Ken-Rad, and more. I must have 25 or so total. The Sylvania Bad Boys are very pricey, I have found less expensive Sylvania, those with the partial Chrome Domes and bottom-chromed to sound good. Solid tubes.

My bargain recommendation, besides the Westinghouse, are Baldwin or Conn labeled Sylvanias. I occasionally see these at around $20. They are decent tubes.

I have listened to all of these in two different Inspire amps, a KT88 Hot Rod and a PSE. Their characteristics are about the same in each amp.

[CohibaJoeLuxman]

I am Very Happy with KT170, KEN RAD CKR-6SN7GT/VT231 and PSVANE WE274B combo. The music POPS from the Zu Audio DW MK.II speakers. Now looking at LP-2030 Pre-Amp...But the Roy Mottram SP14-V22 Pre-Amp I am using is Sweet.