Here is my Circlotron published more than 20 yrs ago.
Based on 6550s, KT88s or 6L6GCs. 50+ watts using KT88s or 6550s.
All the iron by Hammond. No special or boutique parts at all.
And a full page of test data, THD & IMD under various conditions.😀
👍
Based on 6550s, KT88s or 6L6GCs. 50+ watts using KT88s or 6550s.
All the iron by Hammond. No special or boutique parts at all.
And a full page of test data, THD & IMD under various conditions.😀
👍
Here is the datasheet for the EL156. Scroll down to PP amps and find the closest one to the operating point of the amp in question. This gives recommendations.
Telefunken EL156 datasheet
Telefunken EL156 datasheet
Thanks, I was only looking at the recommended bias points and didn't notice the last page was truncated.
I guess the Experience Electronic EL156 design has Chinese made EL156 I. Would it be any difference between the original from Telefunken and the sino version in terms of data of the tube?
Electricity the EL156 is very much like the KT88 & 6550.
But the odd base would be a problem for many this side of the Atlantic.
But the odd base would be a problem for many this side of the Atlantic.
Primary impedance is a function of speaker impedance and ratio of primary to secondary turn ratio.
If speaker is 8 ohms then primary impedance is turns ratio squared times 8.
If speaker is 8 ohms then primary impedance is turns ratio squared times 8.
The label on the PDF on Page One is deceiving. The circuit is not a Circlotron. 👎
It is a 'Plain Jane' PP amp. If it were the two B+ supplies would be identical, they are not.
Referring to the schematic, the plates will be at ~400V while the screens are at ~350V.
Without spending a lot of time trying to adjust the plate curves for G2 at 350V,
I'm going to go with a P-P load of 3K🙂
It is a 'Plain Jane' PP amp. If it were the two B+ supplies would be identical, they are not.
Referring to the schematic, the plates will be at ~400V while the screens are at ~350V.
Without spending a lot of time trying to adjust the plate curves for G2 at 350V,
I'm going to go with a P-P load of 3K🙂
The amp spec claims 90 watts. That would need something like a 2K OPT
with these tubes running on a plate supply of 400.
with these tubes running on a plate supply of 400.
Hello,
I bought old output transformers, initially given for ppEL84, in fact it is ecl86. The required primary impedance is not the same for these tubes. But after reading the article with 16 ohm speakers I found 8K4 in primary. And there, thank you for confirming, I think it's good?!
how I did it: 14v on the secondary of the ot
we measure the voltage which comes out at the secondary Vs : 320
we calculate Vprim / Vs which is the transformation ratio N : 23
we multiply by N² the impedance of the HP that we connect to the secondary and the result is the impedance that the primary presents to the BF output tube
ts ecl86 millerioux
320/14 = 23
23²x8 = 4K2
529x16 = 8K4
Regards, R
I bought old output transformers, initially given for ppEL84, in fact it is ecl86. The required primary impedance is not the same for these tubes. But after reading the article with 16 ohm speakers I found 8K4 in primary. And there, thank you for confirming, I think it's good?!
how I did it: 14v on the secondary of the ot
we measure the voltage which comes out at the secondary Vs : 320
we calculate Vprim / Vs which is the transformation ratio N : 23
we multiply by N² the impedance of the HP that we connect to the secondary and the result is the impedance that the primary presents to the BF output tube
ts ecl86 millerioux
320/14 = 23
23²x8 = 4K2
529x16 = 8K4
Regards, R