Re Tubing Audio Research VT200

Recently I had the opportunity to listen to amplifiers using El34 and others using Kt90 ,...I notice they have the "same" signature : beatfull mid/high, lots of air and tonal equilibrium, mid/low attack , to be short : a lot of musicallity.

I have a VT200 MkII USING svet 6550 and it is time to retube it!

Many people told me to try KT88 , specially Tung Sol.

I have power enough to spare in exchange of even more quality and finesse( I think abou Jadis , wich uses Kt90) if I can find " ideal" tube.

I Love my " impractticall " VT200 monster.... Rsszz

NOS 6550 Winged C or GE 6550GA are known options....
But I wonder if KT90 would be what I am looking for?

I wrote to Arc and to Upscale , asking if Kt90 is a drop in substitute to 6550 or KT88 in VT200 MKII.

Both of them answared that thay have no experience with KT 90 in VT200 MKII.

Do you have any comment or knowledge that can help me if I can or cannot use KT90 in my VT200 Mkii ? And do you thing I am going to obtain the " the finesse" I am looking for?

Thank you for your comments

The repair was about $150 or so, if I remember correctly. The problem is shipping ($500 round trip), which must be on a common carrier. I had to take off work to meet it, and no carriers would insure it on the journey. The best bet is to have ARC arrange pickup and return. When I sold it, I had to use a Pack n Send type business because they would insure it, but no carriers would.

Hi Dbarger,

What did the trace reapir cost, how long ago did you have it done. ARC wants almost $1800 for new tubes.

When I had my VT200 I bought non ARC SED 6550's from a well known Canadian tube seller and found the pin diameter was slightly smaller than the ARC SED tubes. I had one arc, and it cost me $500 shipping plus repairs to send it back and forth with ARC. ARC does extensive burn in and matching on their tubes.
I did use the new issue Tungsols in a VT100 mk2 and found them reliable and good sounding. I also used SED KT88's in that amp without a problem.
The problem as you probably know with the VT200 is the HUGE power supply, which even though a dual mono design takes all the current from both channels through an arc'd tube, taking out a resistor and some traces. They make them that way for the best sound quality, but it is perilous to use questionable tubes.

My VT200 has been retubed with EH KT88 and EH 6922
No problem detected so far (more than 500 Hours of use)
This choice has been done because the KT88 looks more reliable than 6550
ARCL60

Thanks for your suggestion. I assume you never had any problems with the Tung Sol tubes in your VT100 MKII. I will keep your suggestion in mind, Thanks Dave

If you will be retubing power tubes try TungSols 6550 from current production instead of stock Svetlanas. Those tubes take your VT200 to a whole new level. I had them in my ARC VT100MKII and I regret that I changed the tubes so late.

Hi Paul,
I see your disclaimer- what NOS 6922's do you have? I put Amperex Large Logo Bugle Boy's in my PH3SE and they just blew away the stock Sovtek. I was not real excited about it until I made that change. Of course ARC has to deal with what is available on the market, and they charge an increadable amount for them. Did you deal with ARC and the 6550's? Thanks
Dave

Hi...your better off with the new old stock tubes - at least for your drivers - 6922 tubes.

I had a 200 and I liked the 6550 arc stuff - given the prices of the vintage stuff - but the 6922 tubes really made the amp sing! Changed its character a bit - which is what a good set (or sets) of tubes should do.

Discliamer - I am a dealer of New/Old tubes.