@rzaglinskij start removing the gnfb and play with the amp as it is, then substitute one of the two with a pot and find a sweet spot.
mostly I use it with GNFB, sound is more focused and bass is more without reverberations.
I use 12K/470 in R1/R2
I use 12K/470 in R1/R2
Good to have another opinion on it!
It depends alot on the speakers you use (flatter impedance curves sounds fine with low DF amps), the music you listen to (so how tight the bass must be), and the volume you are used to listen to (the higher it is, the most helpful gnfb can be both for DF and THD).
It depends alot on the speakers you use (flatter impedance curves sounds fine with low DF amps), the music you listen to (so how tight the bass must be), and the volume you are used to listen to (the higher it is, the most helpful gnfb can be both for DF and THD).
I still have wood + aluminum top and bottom for this project.... if anyone are interested....
Please PM photos, dimensions, weight and nation to calculate shipping costs. Thanks
Post in thread 'EL34 Baby Huey Amplifier' https://www.diyaudio.com/community/threads/el34-baby-huey-amplifier.326920/post-7380662
I'm in Romania / Bacau / 600121
I'm in Romania / Bacau / 600121
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This is a very nice simple implementation for the builder with almost every needed support circuit on the main PCB.
Well done.
This is a very long thread so please excuse me if i have missed all the performance numbers.
I was wondering for example what THD can be expected at 1 watt at 20Hz , 1Khz and 20Khz.
What is the expected THD at full power at 1Khz. What is the power level at 1% THD at 20Hz and 20KHz.
Square wave response at 1Khz and 10Khz would be interesting to see.
Frequency response showing the -3dB points?
Finally any idea of the damping factor the design provides for loudspeaker compatibility?
Well done.
This is a very long thread so please excuse me if i have missed all the performance numbers.
I was wondering for example what THD can be expected at 1 watt at 20Hz , 1Khz and 20Khz.
What is the expected THD at full power at 1Khz. What is the power level at 1% THD at 20Hz and 20KHz.
Square wave response at 1Khz and 10Khz would be interesting to see.
Frequency response showing the -3dB points?
Finally any idea of the damping factor the design provides for loudspeaker compatibility?
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Tristan's Version (BH EL34 Stereo AIO) is available on Github including Gerber Data for PCB manufacturing
https://github.com/tristancollins/HiFi-BabyHuey
After what seemed like an eternity, another BH EL34 joins the fraternity.
From this ...
... to this ...
... in 4 years.
As my ex-partner used to say, 'Oh wonderful! Another dust collector!'.
From this ...
... to this ...
... in 4 years.
As my ex-partner used to say, 'Oh wonderful! Another dust collector!'.
Nice work Richard. You have finally proved your ex wrong! 😁 Tell us about how it sounds.
If possible, could you do some performance testing? Power, distortion, spectrum analysis. Somehow, BH builders have not published such numbers and graphs, which leaves others with a question. I don’t have such measurement capabilities.
If possible, could you do some performance testing? Power, distortion, spectrum analysis. Somehow, BH builders have not published such numbers and graphs, which leaves others with a question. I don’t have such measurement capabilities.
Thank you. I had a bunch of 11" (28cm) square 3mm aluminum plates cut, which I have tried to used for an various amps, and in every case the challenge is getting everything into such a small footprint. It is nice having it compact at the end, but it takes a lot of creativity to solve some of the issues, so progress is glacial. There is a Toroidy power transformer and a Triad choke underneath, and along with the power supply board. so it is a bit tight.
I flagged up a concern about the trace/pad sizes on the group buy thread. It was not easy to swap a coupling capacitor due to the hole and pad size.
For other builders, I did not bother with the DC supply for heaters. There is a switch for 4ohm/8ohm output between the transformers. Currently GNFB is not connected but I think I will need a little; some loud high pitched vocals sound a tiny bit screechy. IMO there are too many grounds on the boards; I created a central ground on the last PSU capacitor (mounted on the top plate) and tried to just use one ground per board back to that.
I flagged up a concern about the trace/pad sizes on the group buy thread. It was not easy to swap a coupling capacitor due to the hole and pad size.
For other builders, I did not bother with the DC supply for heaters. There is a switch for 4ohm/8ohm output between the transformers. Currently GNFB is not connected but I think I will need a little; some loud high pitched vocals sound a tiny bit screechy. IMO there are too many grounds on the boards; I created a central ground on the last PSU capacitor (mounted on the top plate) and tried to just use one ground per board back to that.