Stanman is your friend just letting you use this piece of gear? I only ask because it wouldn't make to much sense to buy your friend new tubes unless you really like him. I wish I had more friends like you.
Here is a link to an article that talks about this pre-amp. http://www.stereotimes.com/amp040306.shtml
If it is now yours and wanting to play "roll tubes" the choices are very personal and it's hard to say what you will like. I have never used the rectifier used in this unit. But here are my personal opinions on the 12at7. Remember they are my own and other peoples will differ.
I like the German best. I currently use Siemens E81cc in my amp and Valvo 12at7wa in my pre-amp.
The British tubes are nice and have good midrange but seem a little too polite in my opinion. I have Mullard CV4024 and Brimar CV 4024.
I feel the stock Shuguangs are not bad tubes for the price.
Jan Philips 12at7's are not a bad tube and can be had pretty cheap. A bit romantic and slightly rolled off but still darn nice.
Haven't tried any others
Here is a link to an article that talks about this pre-amp. http://www.stereotimes.com/amp040306.shtml
If it is now yours and wanting to play "roll tubes" the choices are very personal and it's hard to say what you will like. I have never used the rectifier used in this unit. But here are my personal opinions on the 12at7. Remember they are my own and other peoples will differ.
I like the German best. I currently use Siemens E81cc in my amp and Valvo 12at7wa in my pre-amp.
The British tubes are nice and have good midrange but seem a little too polite in my opinion. I have Mullard CV4024 and Brimar CV 4024.
I feel the stock Shuguangs are not bad tubes for the price.
Jan Philips 12at7's are not a bad tube and can be had pretty cheap. A bit romantic and slightly rolled off but still darn nice.
Haven't tried any others