Tube rolling and SAC Glowmaster KT88?

First of all, congrats on discovering this amp. There's not to many owmers of this one out there as far as I can tell. Out of interest, what led you to your choice?

I've had a Glowmaster KT88 for a while and have tried using 'winged C' Svetlana KT88's from St Petersburg in place of the SED Svetlana's; to say there was an improvement would be somewhat of an understatement. More depth, clarity, realism and tangible presence. A cracking amp as it is, but changing the output tubes to the winged C's IMHO is a cost effective and dramatic upgrade.

I looked at changing the 6N1p driver tubes, but upon researching this it looks as though whichever manufacturers label is on these, new one's all come from the same factory in Russia. Although there's the option of looking for NOS 6N1p's which seem to come in different flavours as in how closely they were factory matched, differentiated by two letters after the 6N1p i.e. 'EV' or 'IV'.

Hi Mghf, just my thoughts but I hope you'll be as happy as I am after substituting the stock tubes with the Winged C's. To my ears, they're in a different league. Mine sounded better than the original tubes from the off, but really started to come alive and 'sing' after about 40 to 50 hours use, so give them a little time to settle in. Like you, I'd been down the solid state route for many years, and discovered incredible detail but never that elusive something. Then along came valves, and 'another convert is made'.

Interestingly, my first experience with valves was listening to an Art Audio Concerto at Definitive Audio in the UK. My speakers are a little on the hungry side regarding current draw, hence researching and eventually setting on the SAC. Like you, I'd come across the chap who'd had a D200 and his comments also swung it for me.

I've toyed with the idea of NOS 6N1p's but been so happy with the sound of late, didn't really get round to it. If you're interested, have a look on Jacmusic.com - they do some pretty inexpensive NOS 6N1p's.

Newbee, As I'm sure you're aware, there's much politics surrounding the Svetlana brand name. As of present there's...

S Logo (on account of the large 'S' printed on the tube); manufactured at the Refelktor factory, marketed by New Sensor; 'officially' no longer sold in Europe.

Winged C Logo; manufatured at St Petersburg, Russia (These are the real McCoy imho); 'officialy' no longer sold in the US

For what it's worth, the Electro Harmonix KT88 seems to me, on close inspection of the build, exactly the same as the S logo Svets. No surprise really, also being marketed by New Sensor, and made at Reflektor. I could be wrong, but they look carbon copies of one another, just with different print on their sides.

That's fine. Glad you liked them. If you've only had several hours on them, bear in mind that after a good 50 hours bedding in time(in my experience) they will sound far better.

Did you persue the NOS 6N1p's?