It sounds pretty amazing. I wonder if I could put hte KT-150 tube in and expect more. The Midrange is magical.
So I went and met Kevin Deal- nice guy, opiionated- but with good reason.
I bought replacement 6550s to replace my non winged 6550s. Went for the cryro treatment.
OK on leaving Kevin said I should try running them at a lower bias.
Now, As my tubes aged I found the highest I could run the lowest measuring tube was 57milliamps. So i set all the tubes there- and to my surprise the amp still sounded really really good.
So I was still excited to get better Cryoed SED 6550c wing tubes and run the bias back up to 65milliamps.
Kevin asked what I was running at before and I said 57 milliamps which I thought was low, he said "No actually that should sound pretty good".
When I got the new tubes from Kevin - Kevin said I should run them at 57 Milliamps. And at 65 milliamps I would just burn them out sooner and that hte amp sounds better at lower bias.
Of course...the doubting idiot in me thought... "How would Kevin know, he is not an ARC dealer....maybe his tubes can not handle 65milliamps...and besides...I want the best sound...so screw it if the life might be shorter."
So I got them biased the amp to 57 milliamps and it sounded really amazing. After about 20 hours- my main transformer was buzzing from an unrealted issue. I sent the amp back to ARC.
It came back with the tubes biased at 65milliamps. After warm up... it really did not sound as fluid and amazing as before.
So rebiased to 56 milliamps....and it sounded sorta uncontrolled... I thought...well then 57 milliamps likely isn't the sweet spot. So I tried 58.4 milliamps... too controlled, then 57.4 milliamps...still too controlled- WTF???- , then back to 57 milliamps and all was blissful again. Wow.... how can such a tiny adjustment make that sort of difference? I guess I should have tried 56.5milliamps... but frankly I was heated up over this tube amp- and it sounded so good I did not feel a reason to tweek any further.
How Kevin remembers all this stuff is a mystery to me... I won't bother wasting MY time or his time doubting him again. I think he knows his stuff and if he isn't sure ...he doesn't bullshit you...he will just say he doesn't know.
I'm not sure I should change anything because with my Chapman T-9MKII and this GNSC modded ARC VS-110 amp and GNSC Modded Wadia 860x it just sounds ridicoulously real with quite a few recordings... but alas..I had to give up my MIT cable and I have some DH Labs Q-10 stuff which is looking to be promising...getting it back from a cryro in a few days.
Why continue?? ... well I know that the better the system gets you end up with even more recordings that sound absolutley real. right now it sounds like 5-10% of what I play sounds real, I would like to up that to around 20%...whcih probably is about the limit of recorded good material.
So other possible upgrades are the Bob Carver Black beauty modded 305's- possibly The top of the line synergistics cable, and an EAR preamp.
But the tubes seem like something easy to try. Does anyone have a set of KT-150 they might want to try out in my system if I paid a 2 hour rental fee for your hassle? Seems silly to just toss a few hundred buck out just to try them.
