Our amps have 20 watt transformers. I wonder if it's just the design that makes them run hot. I had an Eico HF 81 and that was really hot.

Does anyone have a contact number so I can talk to Dennis? I used to talk to him regularly, but that was when I first bought my DH gear. I have lost his number.

Try googling dennis j had 919

Contact him through ebay.

I'm only thinking about long term stability... like 50 years from now when my son is using the (antique!) amp and I'm long gone.:yes::D

My amp runs hot with certain tube combinations but is that really harmful? :scratch2:

Definitely my 6SN7's produce tangibly less SPL than my 6SL7's, due to the latter's higher gain design, and in my observation, there is a tradeoff involved: The 6SN7 really opens up and allow for more details if you are using a strong, beamy output tube like the KT88 or even the 6L6 GC. If, OTOH, you are using a 6V6, 6AR6, etc., then the 6SL7 is better at providing body and dynamics, without losing details.

Of course, if your speakers are higher in sensitivity than my Tekton Lore 2.0's at 98 dB /8 Ohms, then you would probably enjoy the 6V6 with the lower gain 6SN7 which, other things being equal, is better at detail mining.

KT88's are more suited for body and dynamics, at the expense of possibly masking some micro details, while other output tubes are more detail-oriented but need the boost of the 6SL7. The exception is the 6L6 GC, which can open up all the details available in the recording and still have the body and dynamics to reach an ideal compromise using the 6SN7.

In my amp, both input tube types are interchangeably used without any issues and it uses the 20 watts output transformers. BTW, these run warm as expected, but I have so far never experienced any smelling or excessive heat radiation or anything unexpected from their operation, with any tube combination.

Speaker sensitivity
 

I'm wondering if anyone would like to share his/her personal experiences with the speakers they use for the Inspire gear, and specifically, the sensitivity and impedance values on these?

You can see mine on my previous post. Thanks!

I am driving a pair of ProAc Response 1SC's with my Inspire amp. They have a sensitivity of 86dB/W/m and an impedence of 8ohms nominal. They shine when it comes to imaging and midrange. Good bass response for a small speaker. The Inspire amp drives them to satisfactory listening levels in a small room (even using 6V6's).

I was running Zu Audio Soul Superfly 100db/w at 16ohm with my 6V6 amp fitted with specially wound 16ohm output transformers. That was in my large living room with vaulted ceilings, and I never was able to max out the volume.
I have now downsized and am surprised how well they drive my Kef LS50 at 85db/w 8ohm.
They have may not be able to reach concert levels but I rarely go over 12 o'clock on my Dact volume potted LP-2. They do everything right, imaging, depth, width, separation, and reach out and touch realism.
Maybe it is my smaller room but they sound better with the Kef's than with the Zu's.
http://i128.photobucket.com/albums/p...psoa0axahi.jpg
http://i128.photobucket.com/albums/p...psnsbizjty.jpg