Hi all
Yeah the Frankenstein amp has had some changes made on it. This amp has a 6SN7 Ultrapath and IT coupled to the Single-ended output tubes. This is a stereo single ended output amp that puts out from 2 to about 8 watts per channel with 4,8 and 16 ohm outputs.
What has changed is the output section, the output section was parafeed Single ended outputs. That section had big 80 ma Electra-Print anode chokes and Heathkit A-100 Push-Pull output transformers.
Over the years I found this arrangement didn't really do the Low end much justice. So recently I
stripped out the outputsection and replaced it with a simple single ended design with a One-Electron UBT-2 output transformer.
I choose the UBT-2 for a few reasons:
1) I wannted a quality transformer at a cheap price
2) I neede around 5K so I could still run the 45's, 50's. 183's,300B's, VT-52'sand SV811-3's
3) To have a 4 ohm tap to run type 10's too.
The UBT-2 is a very fine OPT and sounds really good with the Ultrapath 6SN7, I've really been pleased with the change.
So here's the deal, If any of you guys, have a pair of easy to drive HE speakers....
And want to do some Tube Rollin to hear what type 45's, type 50's, 183's, SV811-3,VT-52 and
10's sound like. here's your chance.
There are a couple of adjustments you must dial in on the amp when changing from one set of output tubes to another. Like going from a 300B to a 50 you only need change the filament voltage and the bias current on each tube. Going from a 45 to a 50 you need to change 1) the filament voltage 2) the Plate voltage and 3) the Bias current.
All the changes are easy to do and you can swap out output tubes in a matter of minutes, using Hot Mitts to handle to hot tubes.
Well thats it, we will have another tour this summer, if anyone is interested. Of course this offer only applies to those GASers in the immediate St Louis area.
link:
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1476 Anyone interested ?
Have fun
Willie
