Dennis Had Inspire Amps

[FloridaBoy]

Thanks MA. The scale was tipped when I saw that it will 'massage' Spotify and Tune In Radio. Spotify is rumored to offer lossless for $5 a month more soon too. I am going to compare my modified Havana DAC to it. It's not a Yggdrasil, hopefully it will better the Havana.

[Musica Amantem]

Originally Posted by FloridaBoy

Thanks MA. The scale was tipped when I saw that it will 'massage' Spotify and Tune In Radio. Spotify is rumored to offer lossless for $5 a month more soon too. I am going to compare my modified Havana DAC to it. It's not a Yggdrasil, hopefully it will better the Havana.

I'm sure you will enjoy it.

BTW, I tried the GL KT-88 with the PRE and the Filters ... Terrific! No more boldness, nice and clean sound, and the heavy bass I can control with the volume on my SUB. Now I can use these larger tubes with the PRE without issues. What a relatively simple solution can do!

[x3workshop]

Originally Posted by Musica Amantem

I need to thank you for an excellent suggestion! When you explained how it works, I was convinced, at least on paper, but I really dig it now that I've been using it. It is the single most effective way of improving both seamless low frequencies and improved overall performance in the Amp. It also does not seem to bring any unwanted noises or to limit the original signal in a perceptible way.

6BL7, never heard of it. I know it could replace the 6SN7 in our amps, but not too popular since these are quite rare NOS's. I think I'll follow your suggestion this time around too

You're welcome. I really see no other way of running my inspire with less efficient speakers, as well as being able to use NOS EL34's & new KT77's without feeling like they run out of steam. It also allows me to use 6V6's too with great sonic performance.

Originally Posted by Musica Amantem

I see. That's the way to go .

I'll be trying the larger tubes (6550 / KT-88) with the filters this weekend. I don't expect as much benefit with those, but who knows. Hopefully their over-boldness from the PRE's boost in the signal path will be reduced by not having to deal with those first 100 Hz.

Try the KT120's and even KT150's (with the Fmods) and you will be rewarded with very good tonality without being overly bold.

The 6BL7 is a good substitute for the 6BX7 in the LP-27a and can be used to further refine a tube combo in the inspire amp. You may hate them, but cheap enough to try. Heck, if you'd like, send me a PM with your address and I'll send you one.

Meanwhile... I've been in PP, Ultralinear, and Unity Coupled Paradise for the last few weeks.

If you want to see what I've been listening to I have a thread over on AudioKarma about a High End, Heavy Iron Amp Off. We'll be doing a v2.0 that will include my Inspires vs vintage Japanese SET amps as well as some others mentioned.

[Musica Amantem]

I tested the GL KT-88 and VA 6550 with the filters and you are right, even larger tubes benefit tangibly from this gadget. I'll check your thread at AK.

[Bombadil]

Employing filters and a powered subwoofer is much like bi-amping. Over the past few years I've bi-amped with multiple tube amps and SS amps. My Von Schweikert's bass module has a 4th-order crossover at 200 Hz. As I've mentioned above, I have a preamp which has a built-in filter which I can set at 40Hz to 160Hz. So I run it's output to my tube amps, with the filter set at 160, and then the tube amps to my mid/tweeter modules. I run the preamp's second set of outputs into my SS amp and then to the bass modules.

Then I measure volume levels, typically the SS output is a bit higher, so I insert a high quality passive "preamp" between the active preamp and SS amp, setting the volume level to whatever it needs to be in order to level the volume between the bass module & mid/tweeter module. I used test tones and a SPL meter to do this.

Have done this off & on for several years. Works very nicely with both my Inspire SE HO and a Korato KVA-20 European amp which has Audio Note output transformers and four 6CA7 output tubes to produce 20 wpc in PP triode mode. With the sub-160 signal filtered out, both of these modestly powered amps can play quite loudly.

Both tube amps sound fantastic when relieved of lower bass demands. And the integration between the bass and midrange is very good, as bass module & mid-tweeter modules were designed to work together as a single speaker. In fact the speaker's designer is an advocate for running them in this fashion.

Most speakers don't have a crossover this low. Bi-amping into, say a 3-way speaker with a crossover at 800Hz, would rob one of the wonderful lower midrange from a great amp like an Inspire SE. Also the mid/tweeter module has a nearly flat 8 ohm resistance curve, which is very friendly to a tube amp.

[Musica Amantem]

Interesting! Evidently, unless you are actually bi-amping between mid-range and high frequencies with those two tube amps, the resulting congestion in the signal path would not be necessary if you were to use a std SUB with volume and crossover settings, and a simple High-Pass filter at 160 Hz. If you do use both tube amps simultaneously, I fail to understand how you separate those mid and tweeter frequencies to feed both tube amps?

[Bombadil]

Only using one tube amp at any time. Tube amp into the mid/tweeter module, which handles 200Hz & up, SS amp powers the 4 ohm bass modules (20-200Hz). No subwoofer needed. I love the bass definition and integration from the big towers. I haven't hooked up the bi-amp scenario for several months as I've been listening to how various output and driver tubes sound when driving a full-range speaker. But I will probably go the bi-amp route soon.

I do use an active sub from time to time when driving my Focal Aria 906 monitors. And always when using my Inspire SE EL84 with any speaker.

[Musica Amantem]

Originally Posted by Bombadil

Only using one tube amp at any time. Tube amp into the mid/tweeter module, which handles 200Hz & up, SS amp powers the 4 ohm bass modules (20-200Hz). No subwoofer needed. I love the bass definition and integration from the big towers. I haven't hooked up the bi-amp scenario for several months as I've been listening to how various output and driver tubes sound when driving a full-range speaker. But I will probably go the bi-amp route soon.

I do use an active sub from time to time when driving my Focal Aria 906 monitors. And always when using my Inspire SE EL84 with any speaker.

I see. I guess you do not sense any sound detriments due to the congested signal path, then. I myself wonder how much better (if at all) would my 10" Eminence drivers handle bass, given their originally intended bass application design and the size of the floor-standing cabinet, relative to the SUB. But with this low-power amps the lower frequencies take away the finesse in the mids and highs this amp is capable of when running without filters, although I've had great success running it through the balanced ZBit inputs without PRE. But, today I strongly believe the filters are a must in my rig.

[Bombadil]

I don't know why you find my signal path congested.

Source -> Preamp -> out through #1 outputs with built-in 160Hz filter -> Inspire amp -> Speaker Mid/Tweeter modules
............................ -> out through #2 outputs -> Passive Volume Controller -> SS amp -> Speaker bass modules

Very clean, no signals being crossed from source to speakers, Inspire amp being shielded from all low bass with it's output going into speaker modules which are physically separate and electrically disconnected from the bass modules.

[zip]

I only see a few comments on the Hot Rod versions. Is it just because it is new and there are not many out there ?

10 audio reviews one.