[sneared]

Since all the "good" 5751s are gone or priced astronomically high, I decided to roll some current production tubes, and maybe sift through everyone else's NOS trash.

So to have a baseline for some of my testing, I measured the frequency response of the amp with the stock tubes: JJ ECC83 with unknown driver tubes. The driver tubes were in white boxes labeled 6P14 with no markings on the tubes themselves.

The frequency testing was done driving a pair of HD600s, with the switch on the "high" impedance setting.

Wanna see how the OBH-11/SE compares? Go Here

Surprisingly, the MG-Head has a very smooth frequency response even compared to a solid state amp. I believe Videoshielded had noted some significant frequency peaks, but I didn't observe them.

Note that the high frequency roll off is due to the roll off of the CD player which is down to -1.5 dB at 20 kHz.

I'm getting some new driver tubes so I'm not going to test any more until they come in.

 

[sneared]

Attached is the frequency response with JJ EL84 driver tubes.

I should be doing other things with my life.

 

[Neruda]

interesting! I'm happy to see that my SL-SW860 measures so flat.

 

[braillediver]

I got one of these 5751's last week and it sounds very good. It's 1959. There's a (?) third mica or thin clear disk above the other stuff. The other 2 micas are real thick. It's the best sounding tube I've found in so far.

5751 JAN-JG General Electric (USA)
JAN-JG 5751, 1959 date code. Grey plates. Limit 4 per customer.

JG5751GE$24.95

http://store.yahoo.com/triodeel/12axec7057.html

I am in no way connected or affiliated with the above oganization.

 

[Dusty Chalk]

I thought there were one or two current production 5751's?