New Stasis front end

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#402
Mark Johnson said:
JRW your diagram incorrectly shows the emitter waveform as an inverted version of the input. That ain't right. The emitter waveform will be non-inverted, and the collector waveform will be inverted. The circuit goes by the name "phase splitter" and Texas Instruments used it with spectacular success in their SN7400 line of integrated circuits, in the early 1960s.
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I like your post; thanks. Your approach is akin to say something when one sees something out of place. I make mistakes or bad explanations in my posts. I am still in DIYaudio kindergarden amongs Post Docs in this field. Your [their] timely coaching can only be greatly appreciated by all.

Anton
 
#403
I actually interpreted that point of the circuit as the positive phase input of a balanced input via common base, a little like the balanced input on a differential pair.

As it shows 2 voltage input sources at both points.
 
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#407
Antoinel said:
It is a confusing schematic because the author used: Vneg. Vpos. and Vout. A possible goof by the parent author who may have been thinking/explaining something else. Context unknown! Regardles, this error needed to be called out.
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I don't think so.

By doing negative phase at the input shown, it's inverted to the correct phase at the output.
The positive phase input is not inverted since it is common base.

I think it's intentional like Papa making the correction at the output on his single stage amps.
With a balanced signal you can correct at the input, in the exact manner the author has done it.
 
#408
Have been doing some homework, and the Toshiba 2SA1943 / 2SC5200 outputs are another good candidate for the Stasis. Both Mouser and Digikey have the Toshiba's and also On Semi makes them as well.

So there is a good choice of TO-264 and TO3-P devices around for this amp.
 
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#414
Thank you for putting up with my dumb questions so far. I have ordered the PCBs from JLCPCB and am about to order the outputs - probably A1294 and C3519 because I already have some of those.

I have a couple connection questions.

1. Why are there multiple connection points for V+, V- and LS+? I know the ones on the left side of the board connect to the FE PCB.

2. I assume the speaker positive is connected to LS+ and speaker negative is connected to the PSU ground but where does the PSU ground connect to the OS board?

Thanks for your collective patience.
 
#417
Hi hirscwi, Zen Mod has added the three V+ and V- psu rail connection points to allow for a low impedance connection to the main psu cap bank. Up to you whether you use 1 point or all 3 in parallel. The 3 off LS+ connections also allow you to wire a paralleled lower impedance connection to the loud speaker + terminals, again choice is up to the builder.

There is a power supply GND connection on the RHS of the O/S pcb just under C3, this should be wired back to your PSU star point ground bus, this is only used to connect C3 to ground and does not go anywhere else on the O/S pcb. The loud speaker terminal neg connection should also be directly wired back to the star point GND bus.

Also the 2SA1294 is not a complement to the 2SC3519 although very similar. Difference being in VCEO. Complements are: 2SA1294 and 2SC3263 (230V) and 2SA1386 and 2SC3519 (160V) - but your combo should work fine, as you will be way inside SOA DC curve for both types with the Stasis design.

Hope that is all clear.
 
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