This will be a bit of a rambling post, but I am thinking about buying the Pinnacle.
David Mahler, from reading your above post, it looks like when all is said and done you prefer the TTVJ 307A amp to the Apex Pinnacle with PX4 output because it is more neutral. I know this is a counter-factual and probably there is no real answer, but do you think that if the Pinnacle had a 307A tube option to substitute for the PX4 (as was originally stated in the TTVJ store web page) it would be more neutral and superior to the TTVJ 307A?
In David's Pinnacle thread, Pete Millet said: "For example, I can't stand Grados if driven from a high DF [Damping Factor] amp, but they are OK from a low DF amp."
I have a significant Grado collection and would like it if the Pinnacle matched up well with PS-1, PS-1000, HP-2, HF-2, RS-1, etc., but Pete does not sound too enthusiastic about the synergy. Can you elaborate Pete or any other listers with experience of the Grado / Pinnacle / TTJV 307A match-up?
Finally, great post InnerSpace. Your review may have put me over the top. You gave some indications about the used market for Marconi Osram B65 tube. Do you know of any reputable sellers offering this tube? I'd be willing to try the tube with the Pinnacle or 307A. I see http://www.tejastubes.com/NOSMarconiOsramB65MetalBase.htm but I'd hate to spend this kind of money without knowing the store was legit.
Jesse, iirc the pinnacle has essentially the same circuit as the 307a but it has an external ps, obviously different output tubes, and some upgrades such as better transformers (Dave/Pete/Todd etc please correct me if i've mispoken here). i've heard the 307a a couple of times at canjams and heard the pinnacle at the last canjam, but unlike DM i've not had the opportunity to compare them side by side. i was very impressed whenever i've listened to systems with the older amp, regardless of the phone attached to it. and that included several grados (ps1, ps1000, hf2, & perhaps others) as well as hd800s and some other cans that i can't recall at the moment. the system with the pinnacle did less for me for some reason. was it the output tube, the recabled T1 which gave me some high frequency ear burn (something i've experienced with that phone in some systems), or something else, i just don't know.
are these amps high df amps? if so then my take is different than Pete's as i've never heard the ps1000 sound better than from Todd's system with the 307a. when i had that phone here i just didn't enjoy it nearly as much.
Edited by daveDerek - 3/1/11 at 7:22am