Difference between CK6528 and 6528A ?

[SY]

FWIW, I used a pair of them in PP with 400V B+, 1250 ohms plate-to-plate, and got a solid, low-distortion 90 watts.

 

[webercarbmann]

Hi again

OK - thanks again. The tubes I have are for sure NOS. They came from Kastup Airport in Copenhagen. I got them from a person who works there. He got a lot of tubes when they decided to get rid of some old stuff.

About building an amp with these. I have a set of output trannies made for 300B PP. The problem is that i dont know the load they represent. Does someone know if it would fall in a range that is uaseble for these tubes? I also have a set of output trannies made for 4 x 6550C Paralel push pull. Would these be better?


Thanks again, Peter

 

[EC8010]

For Class A PP, you need about 2k - 2k5 anode to anode for one pair of 6528 triodes (one 6528 - it's a dual triode), and for SE a 2k transformer. If you ratio a 5k transformer (that's probably what your 300B transformers are) by connecting an 8R load across the 16R winding to give a 2.5k load you will lose a little bit of power in the excessive DC resistance of the secondary and the HF performance won't be as good as a purpose-designed 2k5 transformer, but bass may be better. If you feel that SY is too far away to send 6528 for proper crushing, the UK is nearer...

 

[SY]

The 6528 Disposal Center

EC, please, you can't seriously want to pollute your lovely country with toxic waste like that. Be a patriotic European and direct all such garbage to less civilized lands like the US. It's a sacrifice for us, but sacrifice for the good of others is our motto.

 

[fooeywuffle]

6528 Tubes

I have found no difference with any of them, 6528, 6528A, or 6528A/B