Phono Circuit Difference Between Spectral Preamps?

It is the heavy bias and regulation that runs through most of Spectral preamps. A few ventilation slots in the main unit's top plate and things would've been almost solved. However, the factory feels that any chassis open field would be grounds for stray interference and therefore oscillation.
Old time Spectral and owner here.

Fan

I was a (20) yr Spectral owner. DMC 12 Never a problem,(outboard power supply) A pair of DMA 360s, Goodwins original demo pair. Again, never a problem! Waited 5 1/2 months for a Spectral 30SV! For (1) week it was "Magical" Then decided that it did not want to play well with others! First with Manley Steelhead; Then it decided that it did not like my Pass Xono either!
So I recently divorced from Spectral ( was not going to wait for the Mythical Spectral Phono Stage! ) Bought a pair of Pass 160.8s driven directly w/ Manley Steelhead (rolled NOS Telefukens) last night. Wife noticed as soon as she came in the front door ; that the sound was even better!! 
I would have to say: Vinyl, Manley Steelhead (w/ Telefukens) , Pass 160.8s, Avalons. I am one happy guy now! Everything that I have searched for in the last 20+\- yrs has all come together.
The Spectral DMC 12 and power supply both ran Cool. The Spectral 30SV runs warm; just as it states in the manual. Don't know if this will affect its performance/ longevity. Happy that I decided to not put up with its Wide bandwidth circuits! Old tubes and Class A SS is even better.

Dave

This is an ancient post. I know I have spoken with you privately. I have a DMC-10 that I have modified as you are aware. You can adjust the bias current in the output stages to deal with "heat". More importantly, you have to be careful you do not use too high a bias current in the output stages or you will create secondary breakdown issues in the output stage. The user's manual (and a few posts in forums) have recommended current levels that are safe and still sound good.

As to the mystic "wide bandwidth" stability issues, these are dealt with by using modern, upgraded power supply coupling caps. The best 105C electrolytics you can buy bypassed with a large number of high frequency NPO ceramics. These must be used both before and after the solid state voltage regulators. It also helps to put in some series output resistors and these will prevent oscillation with longer capacitive cables. Since I modified my DMC-10 I have never had an oscillation problem, and I had the unit connected to a 500 MHz digital OsCope for over a week trying to capture the nasties. Before the mods, I did see some low level oscillation at 10 MHz. Much over that will not be passed by the series coupling polypropylene caps in any event.