I have a set of PCB's along with PT, swinging choke and OPT pair for sale soon to appear in the 'swap meet' section.
PT (2x one for B+, the other for heaters) are potted and ex military.
The choke and OPT pair are 4k3 with UL taps 8,4,0 and from a 'Burnett Elliot' amplifier; Valve Amplifiers
If you get in touch with Rod Elliot, Elliott Sound Products - The Audio Pages (Main Index) he can tell you how good they are. My take - the BE amplifier was clearly better than the ME850 amplifier which it displaced.
HK in Adelaide
el84 baby huey pcb
Bandol. IIRC you designed a pcb for the original EL84 Baby Huey. How were the results? I intended to build theBH and had some transformers custom made. Unfortunately I have not been able to find the time to complete the project... Yet.
If your el84 board was a success would you be willing to share the Gerber files for that board along with any changes you made to the circuit? If this is not possible has anyone else reading this designed a PCB for the EL84/12AX7 version?
Thank you.
Bandol. IIRC you designed a pcb for the original EL84 Baby Huey. How were the results? I intended to build theBH and had some transformers custom made. Unfortunately I have not been able to find the time to complete the project... Yet.
If your el84 board was a success would you be willing to share the Gerber files for that board along with any changes you made to the circuit? If this is not possible has anyone else reading this designed a PCB for the EL84/12AX7 version?
Thank you.
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Hi,
I have made a last check and found an overlap
I corrected it and made some cosmetic changes like the red LED near the high voltage timer and some improved track routing...
Now it is finished for me and I will send the files to Prasi for production therefor it is the last time to tell us if you find some error
The choke on the picture of the prototype is used for test without load and 240 mA will be enough for an EL84 or a 6V6 amplifier but will be too small for EL34 or KT88 amplifier, 400 mA is recommended...
Regards,
Marc
I have made a last check and found an overlap
I corrected it and made some cosmetic changes like the red LED near the high voltage timer and some improved track routing...Now it is finished for me and I will send the files to Prasi for production therefor it is the last time to tell us if you find some error
The choke on the picture of the prototype is used for test without load and 240 mA will be enough for an EL84 or a 6V6 amplifier but will be too small for EL34 or KT88 amplifier, 400 mA is recommended...
Regards,
Marc
Attachments
Hi,
I have made an other check of the EL34 Baby Huey MK2 and found no error
I have made some little cosmetic changes, increased some tracks size and I will send the files to Prasi today. I already sent the Power Supply files yesterday, therefor we can start production of both PCB
It is last opportunity for the people who want to buy the two PCB to build a super tube amplifier suggested by Ian (gingertube) more than 10 years ago
Ciao,
Marc
I have made an other check of the EL34 Baby Huey MK2 and found no error
I have made some little cosmetic changes, increased some tracks size and I will send the files to Prasi today. I already sent the Power Supply files yesterday, therefor we can start production of both PCB
It is last opportunity for the people who want to buy the two PCB to build a super tube amplifier suggested by Ian (gingertube) more than 10 years ago
Ciao,
Marc
Attachments
Bonjour Christophe,
Thanks for your kind word
I am sure you will love the Baby Huey MK2 ! In fact I discovered tubes amplifiers about 20 years ago when I visited "Portier HiFi" shop in Geneva old town and I bought a pair of Alõn "Petites" Speakers (now Nola) Acarian Alon Petite loudspeaker & PW-1 woofer system | Stereophile.com ! During the discussion with Jean-Pierre Portier, the owner of the shop, he told me that the sound of the speaker was so good because of the tube amplifier
Being in high-tech electronic business I was quite skeptical, as a good professional seller Jean-Pierre give me a brand new Jolida JD502B amplifier Jolida JD-502B Integrated Tube Amp Review [English] and give me one month to return it if I don't like it... As you may guess I still have it 20 years latter
However I was interested to learn how it was possible to improve even more tube amplifier with modern semiconductor available today and the forum on the EL84 Baby Huey started by "gingertube (Ian) was a revelation for me, I was very impressed by the advantage of MOSFET over triode in cathode follower design and constant current source (CCS)... Since I am not good at point to point wiring, I designed a PCB for ECL86, EL84 and finally for the EL34 which became an unexpected success
I am also living in GVA part time, but now I enjoy more often South of France climat and wine Bandol wines - Wines of Provence - Provence Web
Best regard,
Marc
Thanks for your kind word
I am sure you will love the Baby Huey MK2 ! In fact I discovered tubes amplifiers about 20 years ago when I visited "Portier HiFi" shop in Geneva old town and I bought a pair of Alõn "Petites" Speakers (now Nola) Acarian Alon Petite loudspeaker & PW-1 woofer system | Stereophile.com ! During the discussion with Jean-Pierre Portier, the owner of the shop, he told me that the sound of the speaker was so good because of the tube amplifier
Being in high-tech electronic business I was quite skeptical, as a good professional seller Jean-Pierre give me a brand new Jolida JD502B amplifier Jolida JD-502B Integrated Tube Amp Review [English] and give me one month to return it if I don't like it... As you may guess I still have it 20 years latter
However I was interested to learn how it was possible to improve even more tube amplifier with modern semiconductor available today and the forum on the EL84 Baby Huey started by "gingertube (Ian) was a revelation for me, I was very impressed by the advantage of MOSFET over triode in cathode follower design and constant current source (CCS)... Since I am not good at point to point wiring, I designed a PCB for ECL86, EL84 and finally for the EL34 which became an unexpected success
I am also living in GVA part time, but now I enjoy more often South of France climat and wine Bandol wines - Wines of Provence - Provence Web
Best regard,
Marc
Hi TheGimp,
C10 is connected to R13 through the choke or a 10 ohms resistor even if the relay is open
Hi potepuh,
For the functionality this is possible BUT the pinout is not compatible G1 and the cathode are reversed, see the datasheet : https://www.jj-electronic.com/images/stories/product/power_tubes/pdf/7591s.pdf and https://www.jj-electronic.com/images/stories/product/power_tubes/pdf/el34II.pdf
Bye,
Marc
C10 is connected to R13 through the choke or a 10 ohms resistor even if the relay is open
Hi potepuh,
For the functionality this is possible BUT the pinout is not compatible G1 and the cathode are reversed, see the datasheet : https://www.jj-electronic.com/images/stories/product/power_tubes/pdf/7591s.pdf and https://www.jj-electronic.com/images/stories/product/power_tubes/pdf/el34II.pdf
Bye,
Marc
Hello
A friend is interested in BH MK2.
It has high quality 2 opt of 3k5 and another 2 of power (in case of mono-blocks) of 310V and 6.3v 4A (50V bias)
The doubts that arise:
1º It is enough to add more 6.3V or 12.6 (or 12V) transformers for monoblocks.
Are the 2x 6.3V 4A enough for integrated stereo?
2º these 3k5 are viable for BH KT88
3ª In case of a single block, is the TSTA 250/001 (400 mA) sufficient for BH KT88 stereo?
In tests with a prototype, with EL34s and 6L6, 8 ohm cases connected to the 4 ohm secondary, the sound seemed much better than connecting them to the 8 ohm (logical, lower power) already has KT88s but I can't convince you to change and buy EL34s .....
Does size matter so much ???
Thanks to all
Fernan
P.S. sorry for my google translator english
I think that C10 can go with R in parallel, I don't know if it compensates the drainage speed with a 200K for example.
A friend is interested in BH MK2.
It has high quality 2 opt of 3k5 and another 2 of power (in case of mono-blocks) of 310V and 6.3v 4A (50V bias)
The doubts that arise:
1º It is enough to add more 6.3V or 12.6 (or 12V) transformers for monoblocks.
Are the 2x 6.3V 4A enough for integrated stereo?
2º these 3k5 are viable for BH KT88
3ª In case of a single block, is the TSTA 250/001 (400 mA) sufficient for BH KT88 stereo?
In tests with a prototype, with EL34s and 6L6, 8 ohm cases connected to the 4 ohm secondary, the sound seemed much better than connecting them to the 8 ohm (logical, lower power) already has KT88s but I can't convince you to change and buy EL34s .....
Does size matter so much ???
Thanks to all
Fernan
P.S. sorry for my google translator english
I think that C10 can go with R in parallel, I don't know if it compensates the drainage speed with a 200K for example.
Hi Fernan,
You can use 6.3V 4A for a channel (2 x 1.5A for EL34 plus 0.3A for ECC83 = 3.3A per channel)
If you are building a stereo amplifier I recommend to connect the two 6.3V in serie in the MK2 PSU to reduce dissipation in the bridge and to use the DC/DC converter for 6.3VDC !
the 3.5k transformer are acceptable for the KT88, it is a little bit low and you must be careful with the bias and respect the maximum power of the transformer...
YES, the TSTA 250/001 is recommended for a stereo unit several builders (including me) have used it with success
You don't need a resistor in parallel with C10 as explained before !
Rgds,
Marc
You can use 6.3V 4A for a channel (2 x 1.5A for EL34 plus 0.3A for ECC83 = 3.3A per channel)
If you are building a stereo amplifier I recommend to connect the two 6.3V in serie in the MK2 PSU to reduce dissipation in the bridge and to use the DC/DC converter for 6.3VDC !
the 3.5k transformer are acceptable for the KT88, it is a little bit low and you must be careful with the bias and respect the maximum power of the transformer...
YES, the TSTA 250/001 is recommended for a stereo unit several builders (including me) have used it with success
You don't need a resistor in parallel with C10 as explained before !
Rgds,
Marc
Hi Marc!Hi Fernan,
You can use 6.3V 4A for a channel (2 x 1.5A for EL34 plus 0.3A for ECC83 = 3.3A per channel)
You don't need a resistor in parallel with C10 as explained before !
Ok C10 It does not specify 4A, possibly they are more, testing them there was no heat or voltage drops just remembered.
Your answer is a relief, I bought the toroidy a while ago correctly! My budget for a third TSTA 250/001 did not arrive.:confuso:
Just PCBs, another coincidence that went well!
(Sorry for not having 1 game in reserve, maybe someone was interested in changing it to BH84:Oh no
.With KT88s and 4 heavy basic transformers ........ will go on monoblocks adding 10V + 10V standing toroidal internals carefully on the PSU electrolytic and enough power for the DC / DC converter:guay: correct V bias, sec. 6.3V for the other relay delay demand :guay:
All my thanks
Fernan
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Hi all,
Since the PCB are now in manufacturing phase, I will have to make a modified BOM for the Baby Huey MK2 version
There will not be a lot of change since we keep the same schematic but after a suggestion of Ian we will have at least to increase R16 because of the bigger -Vbias power supply, to 39k to 47k...
I will make the BOM and some assembly recommandations before you receive the PCB
Ciao,
Marc
Since the PCB are now in manufacturing phase, I will have to make a modified BOM for the Baby Huey MK2 version
There will not be a lot of change since we keep the same schematic but after a suggestion of Ian we will have at least to increase R16 because of the bigger -Vbias power supply, to 39k to 47k...
I will make the BOM and some assembly recommandations before you receive the PCB
Ciao,
Marc
Hi 6K6 is a good value the "total" power 30 W is a bit low. if you notice vibration, heating (except slight transmitted by the temperature of the 5881s) or a noticeable increase in DHT as the volume increases, You can play lowered + B in the center tap and/or bias setting. I hope someone with more knowledge will tell you the optimal values. Something similar will happen to me, but not with the transformers, with NOS 6P3C (not -E), I have good NOS lot. They work like 6V6s very well, admitting a bigger polarization Is it correct? sorry for my english google translator
Best regards Fernan
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Thank you for the reply. I figured I would need a lower B+ and possibly change the bias. I do have a matched quad of KT-88's, but figured I would try a 6L6 build since I have the OPT's and plenty of 6L6 types. I was hoping someone had built a 6L6 version and would share what power transformer was used. The only power transformers I have left on hand are a Hammond 300BX @ 400v-0-400v and a 300v-0300v from an old console chassis.
The Hammond 300BX is rated at 800VCT 288mA. That's plenty of current capacity for a quad of 6L6 tubes. I'd use a big fat choke of about 7H 300mA and make a choke-input power supply (approx +360V). Run the 6L6s at about Va = 350V and Ia = 57mA (20W plate dissipation). That way you can use older 6L6GB or 5881, or run 6L6GC tubes at below their maximum ratings for very long life, or use Russian 6P3S if you like.
What plate supply current is your 300V-0-300V transformer rated for? Was the console a stereo unit? What kind of output tubes did it run? It nay not have the current capacity for a quad of 6L6s.
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What plate supply current is your 300V-0-300V transformer rated for? Was the console a stereo unit? What kind of output tubes did it run? It nay not have the current capacity for a quad of 6L6s.
--
The 300BX is a bit over kill. The console PT was from a 6v6 PP amp. I get close to 300v out with 120v on the primary. Neither of these are a good fit if I want to use 6L6's. plus Hamond transformers tend to put out more than what the specs say. The 300BX acually puts out a little more than 850VCT due to having a 115v primary.