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CJ PV-2ar or PV-7 or ARC SP-6 for Klipsch Heresy?

I putting together an old school tube-based system to drive an unmodified pair of Klipsch Heresy 1 speakers I picked up on eBay.To give the "old school" a fair shake, I'll be using the best ancillary equipment and tweeks, Transparent Ultra signal cables, and MIT power cables and filtration, etc. Seems to make sense to me to pair them with one of the classic tube preamps of that era such as a PV-2ar, certainly might tame the brightness and "shout". Thoughts?
elunkenheimer
elunkenheimer OP
31 posts
 
For now I intend to use my custom 7591/6sn7, fixed-bias, push-pull amp which uses a Pilot 410 input and phase inverter circuit built on a stripped Heathkit AA100 chassis retaining the great transformers. With this venture into high-efficiency horn speakers, at some point I tempted to try a 2A3 or 300b triode amp. The ALK Engineering site though highlights the seriously flawed crossover impedance curves of vintage Klipsch designs and my sense is that would not make a mini-watt triode amp happy. Should I get serious, an investment in the brilliant, but not-so-inexpensive ALK crossovers would be the next step.
lrsky
1,118 posts
 
I once paired a pair of horns to cj and it didn't work. The noise floor of tubes, in general was too high for speakers with about 100db sensitivity.
Just something to think about.
Larry
atmasphere's avatar
atmasphere
11,784 posts
 
A cj might have too much gain to use with high efficiency loudspeakers.

But to say that the noise floor of tubes in general is too high for speakers of 100 db or more is untrue. The proof of this of course is that most horn speakers are used with tube amps, not solid state. My speakers are 98 db and I have to put my head in the mouth of the horns to hear the noise floor.
elunkenheimer OP
31 posts
 
I agree with Atmashere about "noise floor". With my Tube Technologies CD driving the Heathkit AA 151 into the Klipsch Heresy 1's, it is dead silent between cuts.
raymonda
855 posts
 
I'm not surprised that you have to use the tone controls set they way you do, as Herseys are extremely colored with a balance that leans towards the mid and upper mids. Nice speaker late at night and at low volumes but they fall apart when pushed and have no usable frequency response below 45hz and that is being generous.

They do respond well to tweaks and can be tamed. The caps probably need to be replaced in the crossovers, which may further throw the balance off. While you are at it you can change the internal wiring and stuff them with acoustic insulation, to get another 4-7 hz of bass.

Getting them off the floor at least 18 inches will dramatically improve the soundstage. They are a fun speaker to have a fling with but I found them to not meet my needs for a long term relationship. Your feeling may differ, though.

If you can pick up a Melos SHA1 I found it to work well with them. YMMV!

Enjoy.
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