Wayne's BA 2018 linestage

The amplifier is an Optonica 5100 | Integrated Amp | Power Amp | Pre Amp
Power Amp specs:

poweramp.PNG

Integrated specs
  • Continuous power (at distortion factor) 8 Ohm: 2x 36 Watt (DIN), 4 Ohm: 2x 45 Watt (DIN)
  • Dynamic power 8 Ohm: 2x 47 Watt, 4 Ohm: 2x 75 Watt
  • Total harmonic distortion: 0.05%
  • Attenuation factor: 25
  • Frequency response: 10 - 65000 Hz
  • Signal to noise ratio: 90 dB
  • Stereo channel separation:
  • Tone control: Bass: ±10 dB at 100 Hz, Treble: ±10 dB at 10000 Hz
  • Loudness: Yes
  • High Filter: 7000 Hz/6 dB, switchable
  • Low Filter (Subsonic): 30 Hz/ 6 dB, switchable
  • Mute: Yes
  • Direct/Line-Straight: No
  • Power Amplifier input
  • Pre amp output
Speakers: Magnat All ribbon 6
  • Impedance 4 - 8 Ohm
  • Frequent 28 - 25.000 / 34.000 Hz
  • Cross frequencies 450 / 5.400 Hz
  • Sensitivity 1,2 W
  • Continuous/max 80 / 140 Watt
Mission 761
  • Type: 2 way, 2 driver loudspeaker system
  • Frequency Response: 58Hz to 20kHz
  • Recommended Amplifier: 20 to 75W
  • Sensitivity: 89dB
 
@_Bert_: Have built 8 of the BA2018 pres and used them with 5 monoblock Amp types. Bass response is superb.
You need to look to your Amp and/or your construction. For the Amp I suggest Randall Thatcher's Aleph 30 kit. With case all of the parts will cost around $1200. But it will compare to retail amps at 10 times that cost.
Good to take Zen Mods words as gospel; he's the real deal.
 
I am getting about 16 volts at the output on both sides and neither responds to the potentiometers. I have continuity on all the SMDs, which took a while. Seems odd both sides would have the same error. The 0.1 mF caps, by the way, are the correct value but not the standard make in the kit. I misplaced the kit caps and had these. Any help is appreciated.
IMG_2237.jpeg
 
Oh, good catch on the 1845 transistor. Ugh, I hate desoldering. And I’ll hit that SMD again with a bit of solder. Thanks! D1 looks odd, but it is the kit LED. Do they blink super fast and the camera just caught it? It’s the same brightness as the other LED under power. The incoming power wires are correct, just skewed by the camera perspective. 18v +- from a VRDN PS in all the right places.
 
@_Bert_: Have built 8 of the BA2018 pres and used them with 5 monoblock Amp types. Bass response is superb.
You need to look to your Amp and/or your construction. For the Amp I suggest Randall Thatcher's Aleph 30 kit. With case all of the parts will cost around $1200. But it will compare to retail amps at 10 times that cost.
Good to take Zen Mods words as gospel; he's the real deal.
What is yours opinion on a second hand power amp by Quad, NAD or Rotel, or Yamaha or something in that direction? $1200 is a lot of money for me.

I listened to the pre amp with headphones for the first time, and indeed is has good bass. Going back to the original setup without the preamp is not an option, as I can't go back to that what I find now a muddled sound. So yeah, seems like I have to look for a new power amp.
 
What is yours opinion on a second hand power amp by Quad, NAD or Rotel, or Yamaha or something in that direction? $1200 is a lot of money for me.

I listened to the pre amp with headphones for the first time, and indeed is has good bass. Going back to the original setup without the preamp is not an option, as I can't go back to that what I find now a muddled sound. So yeah, seems like I have to look for a new power amp.
Hi Bert!
Would you mind building your own amp?
I have quite a few PCBs I will never get the time to make into an actual amp. Too many to list, but here is a picture of a few of them
Some notes:
1 - The Bryston 3B is, I believe, the real thing. Comes with dual mono PSU PCBs as well.
2 - Pass Aleph-3 is the same
3 - Accuphase A60 is a simplified and downscaled clone. Has its own thread here with many satisfied followers.
4 - Marantz is also a simplified and downscaled thing. But looks nice....

If you find any of these interresting, I will send it/them for free. For the A60 you may choose the ready-built (except for the power transistors and PSU caps) or empy boards. Your choice. Or take it all.

PCB.jpg


If you want schematics I can post them.

🙂 morten
 
Can you give me a link to the ACA variants?

The cheapest and probably most easy to build of the variants may be the ACA-mini which requires no chassis:
https://diyaudiostore.com/pages/project-aca-mini

Then you have this one which seems to be sold out in the moment:
https://diyaudiostore.com/pages/project-aca-minmax

Then there is the classic amp camp ACA which can be built as a stereo amp, dual mono, bridged etc etc......
https://diyaudiostore.com/pages/project-amp-camp-amp
It seems many likes the dual mono bridged version. So two stereo amps where each stereo amp is configured as bridged.
This configuration should also give you power enough for your speakers. Probably one standard stereo amp will also do the job (depending on how loud your normal listening lever is).
 
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