In my experience, all the 01As and variants are pretty microphonic, with the globes being worse than the ST shape. I also thought that Dennis had some sort of modification that dealt with this issue, but I could be mistaken...:scratch2:

Not that anyone gets it wrong. The LP2030 is one of the best preamps around. the hum and sensitivity of the tubes is minimal. And except for testing, no one comes up with the idea of tapping on the tubes or chassis while listening to music or listening to music with the volume control in the maxilal position. The slight humming is only minimally present at a distance of 2 meters without music.

I have 6SN/L7 and 6C5 which are much worse in this respect and have thrown them away.
the FullMusik 6SL7 mesh, for example, I complained 2 times to the supplier until I had some that made no noise. and that was a hum which felt 3 - 4 times as loud as that of the 01A Coke bottle.

All in all, the whining is at a very, very high level and neither a fault of the amplifier nor the tubes.

The Inspire Speaker is done!
 

Or at least the design is now set. There are some details to finish out, such as determining the retail cost, creating the logo, and determining when we might have the first pairs available, but that will follow soon.

This is the veneer we are planning on using, at least for the first run...

https://live.staticflickr.com/65535/...6b2cf50a_b.jpgUntitled by analog addict, on Flickr




Dennis decided to add a couple of 2" ports and it really brought out the bass, in a very articulated manner.

https://live.staticflickr.com/65535/...b1a6f61e_b.jpgUntitled by analog addict, on Flickr

https://live.staticflickr.com/65535/...18eef9b4_b.jpgUntitled by analog addict, on Flickr

https://live.staticflickr.com/65535/...aa76459c_b.jpgUntitled by analog addict, on Flickr



Running either a new 300b-v amp or my new 6GK6 amp, I was able to FEEL the bass through the furniture/floor. I've never heard bass that good from that small a speaker, even ones that use bass equalizers/active boost.

https://live.staticflickr.com/65535/...b2ed160a_b.jpgUntitled by analog addict, on Flickr


Dennis says this speaker is ready for prime time, so now we just have to determine a fair price.

Stay tuned...

Very interesting design. Looking for to follow up posts.

Inspire 3.1 speakers continued...
 

Dennis has been playing with these a bit more back at the ranch.

https://live.staticflickr.com/65535/...af7d5682_b.jpgUntitled by analog addict, on Flickr

We found that they sounded best with the tweeters on the outside at the shop, but Dennis says at home they sound better with the tweeters on the inside. So...he says he will provide an explanation of what to listen for when new owners are determining placement in their own listening rooms. Meanwhile, I'm pleased and honoured he's using this to power them....

https://live.staticflickr.com/65535/...761fe428_b.jpgUntitled by analog addict, on Flickr

https://live.staticflickr.com/65535/...929c42e9_b.jpgUntitled by analog addict, on Flickr

A text from Dennis a few minutes ago after i asked him the difference between the performance of the 6GK6 and the 6BQ5…

Since the 6GK6 inner structure (lower electrode capacitance) are designed to be used in low power RF driver circuits it reveals a difference in midrange clarity and a lack of that tubby bass found in many of the 6BQ5/EL84 amp signatures. So all in all the 6GK6 tube, audio signature is a refreshing, clean realistic midrange presentation vs the darker tubby EL84 offering. So as I mentioned earlier, I will return your bucket of bolts, 6GK6 amplifier in June or July!!!!

Guess he must like it....


He also said this…

Yep, I’m puttin u on notice .. a mighty Inspire 6GK6’er will be commin soon old man!!!!

Now I gotta convince him to build a 6GK6 PSE…

So what are you estimating the output power of your “ bucket of bolts” to be? If it sounds that good to Dennis it makes me interested. Good job on your part.

well...
 

Thanks. My amp puts out about 4.5 wpc, but I'm running the 6GK6s pretty easy. Now Dennis, OTOH likes to squeeze every last electron of performance out of his output tubes. However, that's the different mindset between a tube collector and an amp designer. I would expect him to be able to get 5-6 wpc out of a set of those tubes.

However, these are inexpensive tubes. I was looking at a nice pair of Sylvania blackplates on EPray that tested almost new and were going for $20 the pair plus $5 shipping. So if the tubes only last for 7500 hours instead of 10,000, who cares?

6GK6 as PSE could be a very good idea.

I know the tubes from guitar amplifiers and there they provide a very clear sound in the midtone range and tight bass.

I'm looking forward to the result.

New speakers look quite intriguing, but currently more interested in the 2030 pre. Not sure I can live without a remote volume control though...ideas on how others have addressed this desire?