Batteries to increase Anode voltage in LoV designs?

[bea]

They were microphonic in regular amps - at high voltage (300V, the preamp i made for my G-2000) as well as at relatively small voltage (120V, V1 position...

[bea]

Did a few tests with old, heavily used tubes - ECC83 and ECC81, both Telefunken, taken from old amps. The ECC83 somehow worked (!) but still was a bit silent....

[bea]

Here in Germany all the well known sources have increased their prices drastically. ANY old tube is a lot more expensive that the newer ones. The times of...

[bea]

No, I have not. I don't own old ECC82. And i actually do not see te need - just in order to be able to run te circuit at 12.5V. It looks as if i even can...

[bea]

That is exactly what i had planned an meanwhile it works like a charm. Even a somewhat worn out 9V battery suffices - i am testing with 8.2V additional voltage....

[bea]

Yes, of course the batteryshall be wired in series with the heater supply for the anodes only. i.e, neg pole of batterie to +12V of the heater and pos. pole...

[bea]

Well, it is about low voltage (tube overdrive...) design. Traditionally run at 12V. Recent tubes, especially JJ ECC82, are fairly unusable at this anode voltage....

[bea]

The Author has published a more theoretical book on using LTSPICE with tube a few years ago, hasn't he?
(I remember from the now defunct roehrenbude...

[bea]

But to which degree can the REALLY be used as EL34 replacements? The old datasheets state a few significant differences:

a) smaller grid leak...

[bea]

Just in order to summarize this visually - note the different positions where the wires are soldered to the caps:

Hum:


...

[bea]

Yes, i know, old thread:



Do You have an idea what makes them so loud?
The stack below is so loud (with the M40) that...

[bea]

Well, actually old, but i did a few measurements on the TM018. Inductance, with a simple multimeter (Peaktech 2005). Measurement frequency apparently 200...

[bea]

Joseph,

exactly that was the impression from my prototype with the thick wire. But nevertheless the 6 mm˛ loop of my prototype produced an at...

[bea]

Whis is exactly what i did. My description on the differences between the signals were based on these. Even for the Primavera, where the loop is larger, overcompensation...

[bea]

mhmm, but that does not explain, why one loop humbucks and the other doesn't.
I still wonder if it is a question of loop geometry.

[bea]

The Sharkfin is Bass 1. Primavera is Bass 2 and looks like that:



last question first: the cavities and the channels are unshielded....

[bea]

Which didn't have any effect in the 2nd case. But a strong one in the 1st.



I'm aware of that. The wavelength is irrelevant...

[bea]

Unfortunately not success at all in the other bass. Same pickup, different coil geometry.


The noise even increases. On the scope the...

[bea]

Success. Here some pictures - one turn, 6mm˛, Talema AX-1500, due to the small cross section of the loop. Sound slightly darker than without the loop, but...

[bea]

That's what i actually expected when i thought about the idea the first time - but i wanted to try. (And it was fun to see an autotransformer actually transforming...

[bea]

I just tried the transformer idea, using a Monacor LTR-110. This is a fairly cheap yet still good line transformer with a secondary for 1:1 and one for 1:0.5....