Thanks Eric, Thanks Zintolo,
I will ask questions once I have read more and have a somewhat working prototype with the old iron I have. I will concentrate on building the BHEL34 first, to gain knowledge before attempting other builds. Thanks for the help, all the best in the future. Keep safe.
Myles
I will ask questions once I have read more and have a somewhat working prototype with the old iron I have. I will concentrate on building the BHEL34 first, to gain knowledge before attempting other builds. Thanks for the help, all the best in the future. Keep safe.
Myles
Just as a suggestion for non standard tube users for this design (more Yves one than Ian one, due to the need of a lower voltage on screens):
https://frank.pocnet.net/sheets/009/e/E130L.pdf
This tube has:
mutual conductance of 27.5 ma/V
plate dissipation of 27.5 W
internal resistance (in pentode mode) 10 kOhm.
It is designed to give 60Wrms with 9 Vrms on g1.
https://frank.pocnet.net/sheets/009/e/E130L.pdf
This tube has:
mutual conductance of 27.5 ma/V
plate dissipation of 27.5 W
internal resistance (in pentode mode) 10 kOhm.
It is designed to give 60Wrms with 9 Vrms on g1.
Hello ,
I am finally getting back on the construction of the amp I just received the box today someone will have a template or the 1: 1 scale image of the amp board for drilling the box.
cordially
Steven
I am finally getting back on the construction of the amp I just received the box today someone will have a template or the 1: 1 scale image of the amp board for drilling the box.
cordially
Steven
I finally found a high voltage relay for the power supply of TE connectivity reference 2-1904058 . However I see to order it it requires 240ma , in your opinion I can replace the 2n3906 with a BD140 or a MJE350 to drive it without problem? We also need to recalculate the R7 resistance.
cordialy
cordialy
Ouch! I see Mouser (in USA) charges $64 for that relay! There must be a relay that can do the job for a bit less money.
I bought this relay upon recommendation of someone who claimed he had been using it for years without trouble to switch tube power amp B+, but I have not tried it out yet. RTE44012F TE Connectivity / Schrack | Mouser
I bought this relay upon recommendation of someone who claimed he had been using it for years without trouble to switch tube power amp B+, but I have not tried it out yet. RTE44012F TE Connectivity / Schrack | Mouser
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I just ordered it from farnell for 44 euros with shipping costs . This is the only most affordable one I can find with a voltage of 460vdc max ,I just have the worry for the control transistor 2n3906 and too low should I replace it with a more powerful one
Hello, I am blocking on the calculation of the resistance R7 to replace the 2n3906 by a more powerful transistor like the bd140 or others to mount my high voltage relay which has a coil resistance of 50 ohms in 12v for 240ma . Normally the calculation is done with this formula ohms R7 = (Wine – 0.6): ( ib: 1,000)? ? ? If someone can help me on this problem, it would be good
Yes, I’m here and also waiting for the experts to help with your “wine - 0.6” formula 😀
Meanwhile, I looked at the specs of the Lm555 IC and shows its output can source (or sink) 200ma. So, I think any reasonable transistor that could handle your 250ma will be fine here. R7, I believe, is there for good measure and could remain as is. But I would also like the experts to speak on the issue.
Thanks Francois,
I wasn't aware of that way of saying, now I understand.
I agree with you to keep that value as is, while for the transistor a TO126 PNP like the cheap BD140 is IMO fine ( https://www.mouser.com/datasheet/2/149/BD140-888626.pdf ).
I wasn't aware of that way of saying, now I understand.
I agree with you to keep that value as is, while for the transistor a TO126 PNP like the cheap BD140 is IMO fine ( https://www.mouser.com/datasheet/2/149/BD140-888626.pdf ).
I would like to have some feedback on the general consensus for Hammond output transformer for EL34 in the Baby Huey:
Hammond 1650G: 6k6Raa, 35W, max 200 mA, less than 80€.
Loadline stays below max plate dissipation at B+ = 400V, power is around 36W (loadline hits 60V at 210mA).
Hammond 1650H: 6k6Raa, 40W, max 200 mA, around 95€.
Loadline stays below max plate dissipation at B+ = 400V, power is around 36W (loadline hits 60V at 210mA).
Hammond 1650P: 6k6Raa, 60W, max 200 mA, around 110€.
Loadline stays below max plate dissipation at B+ = 400V, power is around 36W (loadline hits 60V at 210mA).
Hammond 1650R: 5kRaa, 100W, max 318 mA, around 110€.
Loadline hits 318mA at 87V with B+ at 480V and 62Wrms.
Loadline hits 294mA at 84V with B+ at 450V and 53Wrms.
Hammond 1650N: 4k3Raa, 60W, max 318 mA, around 110€.
Loadline hits 318mA at 108V with B+ at 450V and 55Wrms.
Hammond 1650G: 6k6Raa, 35W, max 200 mA, less than 80€.
Loadline stays below max plate dissipation at B+ = 400V, power is around 36W (loadline hits 60V at 210mA).
Hammond 1650H: 6k6Raa, 40W, max 200 mA, around 95€.
Loadline stays below max plate dissipation at B+ = 400V, power is around 36W (loadline hits 60V at 210mA).
Hammond 1650P: 6k6Raa, 60W, max 200 mA, around 110€.
Loadline stays below max plate dissipation at B+ = 400V, power is around 36W (loadline hits 60V at 210mA).
Hammond 1650R: 5kRaa, 100W, max 318 mA, around 110€.
Loadline hits 318mA at 87V with B+ at 480V and 62Wrms.
Loadline hits 294mA at 84V with B+ at 450V and 53Wrms.
Hammond 1650N: 4k3Raa, 60W, max 318 mA, around 110€.
Loadline hits 318mA at 108V with B+ at 450V and 55Wrms.
Thanks for your answers I will leave the resistance r7 to 1k and I will try with a bd140 transistor. I’m in the middle of building the amp right now, the chassie part and the longest to achieve .
Cordialy
Steven
Cordialy
Steven
Good evening,
I must inform you of a sad news, Marc died last Thursday.
His funeral will take place tomorrow.
We did some great electronic projects together, it was a real pleasure.
A page turns and the book closes permanently.
My Baby Huey will be our last memory together.
RIP my friend
I must inform you of a sad news, Marc died last Thursday.
His funeral will take place tomorrow.
We did some great electronic projects together, it was a real pleasure.
A page turns and the book closes permanently.
My Baby Huey will be our last memory together.
RIP my friend
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