Hybrid

[nitelite]

Have McCormack DNA-1 would like to read thoughts on using exsting parts and rpacing driver stage to TUBE From an article I read in audioXpress Feb.2001 by Marco Ferretti. My power amp works just is older unite that has seen repairs from questional sources.

[Eli Duttman]

As nobody has replied, I'll put my 2 cents in.

I am not familiar with either the McCormack amp or the magazine article; so, no comments on them. I own and happily use a number of hybrid components, including an AVA FET-Valve power amp. The hybrids do sound GOOD. Since the folks behind the magazine don't publish the work of charlatans, I say go for it!

[G]

you should be able to do it with some clever alterations of the power supply and a 6DJ8. They are said to sound good at low voltages. I have read that some tubes sound so warm at low voltages that they are actually a caricature of a tube circuit. They sound nice for a short period of time and then you realize they have totally changed the sound of the music into a sickly sweet miasma. Kind of like eating too many pralines.

[Eli Duttman]

The 6DJ8 will work with lowish B+ rails, but may not work at the LOW voltage found in the SS amp. However, the 6GM8, which is related to the 6DJ8, WILL work. The 6GM8 was designed to be battery powered in automotive applications. The max. anode voltage allowed for the 6GM8 is all of 30 V.! Like its relative, the 6GM8 is highly vulnerable to parasitic oscillation. 1 KOhm Carbon composition grid stopper resistors and 100 Ohm Riken Carbon plate stopper resistors are indicated. Here's a link to the 6GM8 spec. sheet. http://frank.pocnet.net/sheets/035/6/6GM8.pdf