AKSA's Lender Preamp with 40Vpp Output

[Vunce]

Next question: It sounds I will need more amp power. Can get another Pass ACA, would it make enough power for a variety of speakers or should I swap to something else with higher power to build? Would want something that sounds as good as the Pass.

Hi Maf_au,
Since you have just built the Aksa Lender preamp it’s a perfect match for the MoFo, check out this thread:

Build This MoFo!

You can get about 10-11wpc with your 19vdc power supply.

If you want a bit more power check out the ALPHA20 amplifier:

Aksa Lender P-mos Hybrid Aleph (ALPHA) Amplifier

Both of these amps are Terrific!! Well worth building them. 😉

 

[xrk971]

I couldn’t have said it better than Vunce. The MoFo driven by the Aksa Lender is one of the best 10w+ amps out there. Although, You can take the MoFo to the next level by increasing voltage to 37v and bias current to 4.5amps to get a 50w amp. 🙂

Only problem is that it becomes a 150w (per ch) room heater.

 

[xrk971]

A new variant of Aksa Lender Preamp with dual rails and DC coupled output capability.

The YARRA Preamplifier/HPA for Melbourne DB Group Buy

 

[Fitero]

xrk971 was great! When the USPS destroyed the package and lost the boards he sent a replacement set immediately. No better customer service can be had anywhere!

I ripped out the guts of the tube preamp chassis that I made to go in an old radio enclosure and re-purposed it for the AKSA, Lender preamp.

I made it with @ 6db gain as it is only feeding an external BSS processor, which is the crossover for my speakers. I think the gain is perfect.

I have only been listening to it for the last few hours, so expectation bias is inevitable. That being said, I really am thrilled with it. Unless I am fooling myself, it has given my system that nuance of holographic realism that had been missing since transitioning from the VTA SP-14 preamp and AKSA Maya-200 amplifier to my current system.

 

[Vunce]

xrk971 was great! When the USPS destroyed the package and lost the boards he sent a replacement set immediately. No better customer service can be had anywhere!

I ripped out the guts of the tube preamp chassis that I made to go in an old radio enclosure and re-purposed it for the AKSA, Lender preamp.

Fitero,
Really cool, unique look for your AKSA Lender preamp!!
It’s a fantastic preamp and very versatile, ENJOY 🙂

 

[xrk971]

Hi Fitero,
Thanks for the kind words. I am glad you made quick work of the replacement board that I sent. You have a very nice looking unique preamp there! I live the vintage wooden cabinet look. What did you do with the Maya?
Cheers,
X

 

[Fitero]

Thanks for the kind comments.

Curiously enough, I sold the Maya to a member here who lives in Canberra, so the amplifier made it's way back home more or less.

I am very happy with what I hear. My speakers are ruthless. The few other devices that I have inserted in the signal chain took away from the quality of the music in my opinion. This preamp has not as far as I can tell.

 

[Fitero]

I've spent the last few days swapping out different value input caps, and bypassing the other capacitors on the main board until I got the sound that I was most pleased with. Each change caused a very subtle change in either bass or treble.

I am convinced that this has been the most cost effective purchase that I have ever made with regard to a stereo component. I really hope that many more people assemble this awesome preamp.

I'm back to foot-tapping, head-bobbing and enjoying my music and not contemplating the next change.

 

[maf_au]

If the sound happens only on high crescendos then it sounds like your ACA is clipping. You can tell if you connect a more powerful amplifier and crackling goes away. ACA is limited to 5w rms for 19v supply. 5w is 18vpp. Tweeters often draw high voltage transients on crescendos.

Hi.

Finally pulled out my old Musical Fidelity P150. Connected it and turned it on. The output was huge, had to turn it off and bring the volume way down! The ACA was at around 80% on the volume and crackling and the P150 is around 25%, louder and no crackling.

The sound from the MF definitely isn't sounding as good as the ACA but it is an old ancient amp. Shows that the ACA is way too low in output in our system.

So now have to decide what to build - the extra ACA, the MoFo or something else.

Now knowing that the ACA is way too low, would either of them have enough power for our system? The MF150 is 150w

 

[maty tinman]

Hi.

Finally pulled out my old Musical Fidelity P150. Connected it and turned it on. The output was huge, had to turn it off and bring the volume way down! The ACA was at around 80% on the volume and crackling and the P150 is around 25%, louder and no crackling...

Musical Fidelity P150 owners take note!

Maybe is a good idea to change the original PSU caps. With good 80V/100V 105 ºC and low ESR. Or a full recap.

 

[maf_au]

Maybe is a good idea to change the original PSU caps. With good 80V/100V 105 ºC and low ESR. Or a full recap.

All done, months ago! 😀

Musical Fidelity P150 owners take note!

 

[maty tinman]

What are some good MOSFET amps? | Page 5 | Audiokarma Home Audio Stereo Discussion Forums

Musical Fidelity P150 2x75W - 1 pair Hitachi 2SJ50/2SK135 (P140 with better transformer)

Maybe you could replace the power cord with a more audiophile one [ironic way] 😀

I would not spend more money on that amplifier.

You need speakers with higher sensibility or power amp with more watts. Bad idea to build a new ACA to your speakers, I think.

 

[maty tinman]

I would further separate the transformer cables from the speaker connectors.

[IMG, link] https://i.postimg.cc/057Jnw0k/IMG-4540b.jpg

[IMG, link] https://www.hifido.co.jp/photo/08/192/19298/b.jpg

You can add a Schaffner FN9244B 3A RF/EMI inlet filter to the external power cable. New cheap power cable and nothing more. Bought (PC, computer) or built/DIY with star quad geometry.

- End off topic -

 

[maf_au]

Thanks from maty,

I'm not interested in using the MF P150. Only using it to check the problem of the ACA. It's an old and not well made design or build of it.

 

[SuppersReady]

I've finally got the Aksa in to a chassis. It's not the tidiest of wiring but I've learnt from the mistakes made along the way. It's getting a bit of burn-in through some ancient music centre speakers that I keep for such occasions. I'm very much looking forward to tomorrow when it gets connected to the main system!

 

[maf_au]

Looks good SuppersReady!

Have ordered the similar black chassis for my Lender. Matches with the ACA. Mine will have a power switch on the front like I have on the current ACA face, and the volume and input switch.

Finally decided to buy the second ACA Amp, and also the MoFo. The single ACA is just a bit lower power for my speakers.

 

[xrk971]

Look great, Suppersready!

 

[GASCo]

Looks good SuppersReady!

Have ordered the similar black chassis for my Lender.

Mind to share a link for this chassis?

Tks

 

[maf_au]

Yep, comes from the diy audio shop:

Galaxy 2U w/Steel Covers - Quantity 1 / 230mm x 230mm / 10mm Black x 1

 

[maf_au]

Here it is:

With Steel covers:
Galaxy 2U w/Steel Covers – diyAudio Store

With Aluminium covers:
Galaxy 2U w/Aluminium Covers – diyAudio Store

Several dimensions of the box available. Ordered it with 10mm black front, and with the steel covers.

Can also order it with no screws on the front.