Ok, I measured while turning the volume up and down now. Without a source connected it peaked out at around 140mV. With a source it goes down to maximum 35mV. Feels pretty safe as long as a source is connected, which is how I usually listen to my amps
What did you measure?
I didn't match anything, just the standard BOM. Did you do any tweaks to tame it? I recall Russ mentioning reducing the resistor at the input to GND to tame the DC offset with no source connected. That would be RZ if Im not mistaken.
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Would 2N3904 + 2N3906 pairs be applicable in the original Diamante schematic? Mostly just for building a test version
Yes those parts should work just fine.
Thanks for your fast reply! I only appear to have 12 pairs of those annoyingly, but have 9 pairs of 2N5401 + 2N5551 also, can mabye use those for the output devices, is mixing these ok so long as I keep the pairs complemtary?
Ultimately, I'm looking to test this design as a low power, high performance power amplifier:
http://www.diyaudio.com/forums/solid-state/165331-low-power-discrete-designs.html
Using BD139/140 pair(s) on the output. I guess I'd also need to lower the emitter resistors (shown as 10r) and output balancing resistors (shown as 6.8r) for use driving speakers.
Ultimately, I'm looking to test this design as a low power, high performance power amplifier:
http://www.diyaudio.com/forums/solid-state/165331-low-power-discrete-designs.html
Using BD139/140 pair(s) on the output. I guess I'd also need to lower the emitter resistors (shown as 10r) and output balancing resistors (shown as 6.8r) for use driving speakers.
Oops, I was looking at an old schematic. I am building this one (v1.1):
http://www.twistedpearaudio.com/misc/diamante_DIY.zip
Nearly finished on breadboard
http://www.twistedpearaudio.com/misc/diamante_DIY.zip
Nearly finished on breadboard
Hi Russ, Brian and Mr Majestic,
I used Mr Majestic boards which I bought some time ago and built this amp for my headphones.
Well as usual I'm impressed with another of Russ's designs. Great work guys I think this is my new reference. I think at this early stage I prefer it to my M3 and F4, both great amps. The diamante seems to do everything well and is quite a well balanced amp. Example, the M3 has better dynamics and air, but it seems its highs are not as natural and the mids a little recessed. Its quite ell known for its bass I think. The Diamante matches it for bass, less air and stage and dynamics, but it seems a more natural presentation and I like the highs more.
There is a slight stability issue I think, I got the scope out and there was and underlying oscillations, it went away I thought it was interference or lead problems. I notice now if I put my fingers on the transistors I get a louder humming noise, offset sees to drift a little, from a round -6mV to 40mV. Bias is stable. I dont have a pot and wiring is not yet routed opytimally.
Russ how does it compare to the ventus?
My next HP amp will be the Gilmore Dynalo, I really got to stop building these things.
BTW Mr Majestic, have you got any more of these for sale, I could use a couple for the buffalo 32S I'm building.
I used Mr Majestic boards which I bought some time ago and built this amp for my headphones.
Well as usual I'm impressed with another of Russ's designs. Great work guys I think this is my new reference. I think at this early stage I prefer it to my M3 and F4, both great amps. The diamante seems to do everything well and is quite a well balanced amp. Example, the M3 has better dynamics and air, but it seems its highs are not as natural and the mids a little recessed. Its quite ell known for its bass I think. The Diamante matches it for bass, less air and stage and dynamics, but it seems a more natural presentation and I like the highs more.
There is a slight stability issue I think, I got the scope out and there was and underlying oscillations, it went away I thought it was interference or lead problems. I notice now if I put my fingers on the transistors I get a louder humming noise, offset sees to drift a little, from a round -6mV to 40mV. Bias is stable. I dont have a pot and wiring is not yet routed opytimally.
Russ how does it compare to the ventus?
My next HP amp will be the Gilmore Dynalo, I really got to stop building these things.
BTW Mr Majestic, have you got any more of these for sale, I could use a couple for the buffalo 32S I'm building.
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I'm all sold out I'm afraid. I do have four assembled boards if you are interested.
Hi Mr Majestic,
Have you got any instability problems with your build? I have two that have oscillations at what appears to be 200mV P-P. I cant understand whats going on because this is the same level as the music when its loud, yet teh amp sounds very good apart from sone background hum.
Anyone know how I can stabilise the amp, I have used every part as per the BOM, there are no differences to the original schematic.
Have you got any instability problems with your build? I have two that have oscillations at what appears to be 200mV P-P. I cant understand whats going on because this is the same level as the music when its loud, yet teh amp sounds very good apart from sone background hum.
Anyone know how I can stabilise the amp, I have used every part as per the BOM, there are no differences to the original schematic.