Lovely setup there, Vunce. Must sound fantastic. I have always liked the older Klipsch super efficient speakers. Probably 4w and you are rocking pretty hard.
The AC voltage rating for ''small'' (huge in comparison to all japanese caps)sized Mundorf electrolytics rated 63VDC is 23VAC. What is amount of DC the AC output ''rides'' upon with Lender/MoFo ?
It rides on half the Vcc or for 46v it’s at about 23vdc. I have taken this amp as high as 60v or 30vdc half point for output cap. If you swing +/-25v that’s 55v max, correct?
Feels that way, but AC rating for these seem more Dc=Vpp
www.ftcap.de/fileadmin/user_upload/...atoren/webboxen/axiale_Kondensatoren/ATBI.pdf
www.ftcap.de/fileadmin/user_upload/...atoren/webboxen/axiale_Kondensatoren/ATBI.pdf
Lohk and Johngalt47,
Sure, there are more boards. Please PM me your PayPal address and I will send you invoice.
Sure, there are more boards. Please PM me your PayPal address and I will send you invoice.
Sign me up for the same two sets!
PM sent with mailing and paypal info.
Where do we look for the amp ideas based on this front end, X?
Scott
Ok, will sign you up as well.
Here are some amps to use this pre with:
MoFo - tested and verified to produce 11Wrms
F4
F4 Beast
SEWA
But I have also found that it helps make low gain amps like most Pass Class A amps sound better (they have typically 14dB to 20dB) and have a hard time reaching clip with normal line level outputs.
So F5, F5Turbo, F6, F7, M2, Aleph J, etc... can all sound better with this front end.
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X,
Thanks for the amp recommendations, I'm currently mid way through my first, the Amp Camp Amp, and all the power info from this thread will help that.
AKSA wrote, "Output is low impedance (<5R), but limited to 12mA CCS. This can nicely drive a small output stage, single ended or PP. The buffer, Q4, could be made a FET or even increase current to 30mA. That would boogie!"
...and I was hoping to sucker you into signing up to come up with an amp implementation. ;-)
Thanks for the amp recommendations, I'm currently mid way through my first, the Amp Camp Amp, and all the power info from this thread will help that.
AKSA wrote, "Output is low impedance (<5R), but limited to 12mA CCS. This can nicely drive a small output stage, single ended or PP. The buffer, Q4, could be made a FET or even increase current to 30mA. That would boogie!"
...and I was hoping to sucker you into signing up to come up with an amp implementation. ;-)
It also would drive the Silicon Harmony very well - that is not a public DIYA amp though (it's available on my Etsy shop). I forgot to mention another very easy to build amp that would work great with this preamp is the DLH. PCBs are avaible from Prasi. That is one of the finest Class A amps to come along in a while. Very simple and very low distortion.
Hugh and I could probably come up with a decent buffer amp to go with the Aksa Lender for the DIYA community. Give us a few days 🙂
If you want something to go after right now - try the DLH. It's really good.
Here is 2.83Vrms into 8ohms for the DLH. Most Class A amps from the Pass forum would have a hard time getting 0.002%THD and a nice profile like this:
THD and components Vs Freq:
Here is how simple it is:
With stereo and my monster cap bank:
I made a tiny SMT version for a headphone amp:
Anyhow - check it out and pair it with Aksa Lender.
Hugh and I could probably come up with a decent buffer amp to go with the Aksa Lender for the DIYA community. Give us a few days 🙂
If you want something to go after right now - try the DLH. It's really good.
Here is 2.83Vrms into 8ohms for the DLH. Most Class A amps from the Pass forum would have a hard time getting 0.002%THD and a nice profile like this:
THD and components Vs Freq:
Here is how simple it is:
With stereo and my monster cap bank:
I made a tiny SMT version for a headphone amp:
Anyhow - check it out and pair it with Aksa Lender.
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So.... Hugh and I were just talking about this and in fact we have a new power amp to share. But I must first build and test it. It will have an Aksa Lender front end built-in so no need to use your Aksa Lender pre to drive it - although wouldn't hurt to use it for volume control. The amp will be Class A of course, and SE Class A, but with adaptation of a famous CCS. It will use the usual +/-24v and have a bias current of circa 1.6amps. Output power in the range 25w or so into 8ohms. But the special thing is that it will be relatively low distortion for a SE Class A amp, and have the usual nice harmonic profile of dominat 2nd order and monotonically decreasing higher orders. I am looking over the schematic now and debating whether or not to make a layout on copper PCB and hand etch, or just P2P it on veroboard.
Great news 🙂
Might be interesting to try also small AB class amplifier approach with this distortion profile, with the same idea working as a buffer. Some 50 watts would satisfy most of the needs 😉
Might be interesting to try also small AB class amplifier approach with this distortion profile, with the same idea working as a buffer. Some 50 watts would satisfy most of the needs 😉
Some progress - all built up and now need to double check circuit routing and connections against diagram before applying power. The aluminum bar is used to clamp an IRFP240 and IRFP9240 against a copper block cooled with heat pipes and fins from a CPU cooler. Hopefully good enough for 80w. 😀
Attachments
That’s actually something we considered. But in the end, we thought a novel SE Class A design would be more fun. Certainly, you can use the Aksa Lender to drive the wonderful Ranchu-Aksa Quasi amp. That amp is perhaps one of my favorite 50w Class AB amps ever. It’s well documented and proven and highly highly recommended if you haven’t made it before.
My build of Ranchu-Aksa Quasi:
The new Class A amp that I am building above (code named the ALA amp), if using appropriate high dissipation MOSFETs capable of 80w ea and a +/-35v supply will get 53w (unclipped 0.043%THD) into 8ohms in pure Class A. Quite a formidable output with low distortion but the cooling requirements are probably way above what most heatsinks on typical DIY builds can handle. Unless you go fan cooling route (one of the above heatsinks per output so x4 for a full stereo amp).
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As Butch Cassidy would have said about Hugh and you, "Who are those guys?"
(Quote from movie: Butch Cassidy and the Sundance Kid) 🙂
😛I haven't even built my MoFos yet and there's another Class A design on the way?!?! Either way I have two of these waiting. 😀
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