Does anyone have experience with (or opinion regarding) the attached (PCB and schematic) for the "XE350" (XE350C) supposedly based upon Accuphase?
I am interested in finding out if the schematic and layout is good or whether there are errors or departures that are problematic. I ask since a number of years ago I tried a MA9S2 kit before finding out how different it was from the real thing.
Is this XE350C worth building? Is there a better one to try? Other alternatives that I am wondering about as the potential next project include the Symasym 5-3 or the APEX A40.
I should note that I am only looking at the bare PCB. I intend to use used genuine parts (mainly) from recycled receivers.
I am interested in finding out if the schematic and layout is good or whether there are errors or departures that are problematic. I ask since a number of years ago I tried a MA9S2 kit before finding out how different it was from the real thing.
Is this XE350C worth building? Is there a better one to try? Other alternatives that I am wondering about as the potential next project include the Symasym 5-3 or the APEX A40.
I should note that I am only looking at the bare PCB. I intend to use used genuine parts (mainly) from recycled receivers.
Attachments
the scheme is similar to the original, like a horse to a donkey: it seems to be similar in appearance, but the racetrack will immediately reveal the difference
What are the specific flaws? Are they practically fixable?
Or is there a better starting point out there that you can recommend?
Or is there a better starting point out there that you can recommend?
Trying to answer my own questions I found the Accuphase brochure online for the E350. In that there is a circuit diagram that seems to closely match the schematic for the eBay PCB. The eBay schematic (post #1) actually looks promising in comparison to the Accuphase brochure.
In addition I can see some of the transistor types/brands (Sanken) and I have suitable devices. (The brochure includes photos of the modules.)
Can anyone add any specific insight? Has anyone built an Accuphase clone? If so, can you link to the gerbers or PCB or kit?
In addition I can see some of the transistor types/brands (Sanken) and I have suitable devices. (The brochure includes photos of the modules.)
Can anyone add any specific insight? Has anyone built an Accuphase clone? If so, can you link to the gerbers or PCB or kit?
Attachments
The Vbe multiplier is a little dangerous.
With pot at one end the Vbe voltage output will be very high turning on all outputs like a short.
I usually cap Vbe voltages with a zener across the whole circuit.
A Zener is cheaper than replacing all your outputs.
Or even a resistor in series with pot to limit its range.
With pot at one end the Vbe voltage output will be very high turning on all outputs like a short.
I usually cap Vbe voltages with a zener across the whole circuit.
A Zener is cheaper than replacing all your outputs.
Or even a resistor in series with pot to limit its range.
I do like to select a reasonable resistor and trimmer value for an appropriate bias range. I always set the trimmer (for minimum bias) and measure with my meter before soldering it. Plus I did build a dim bulb tester. (I have also used current limited dual regulated supplies for first turn on.)
I am hoping someone out there has built an Accuphase clone and can comment on the best gerbers, bare PCB or kit to start from.
I am hoping someone out there has built an Accuphase clone and can comment on the best gerbers, bare PCB or kit to start from.
Exactly! That is the right question: tell me what to do instead of what you think?
It is really interesting how people "answer" to direct, practical questions with plain personal opinions. We all should know that personal opinion is the lowest degree of knowledge which doesn't require neither accountability nor understanding.
So, let me answer your quiestion. There are several Chinese clones that attempt to ressemble your schematics. I have built several Chinese Accuphase "clones" which measure rather fine or should I say they measure exactly how a good amplifier should measure. Can you imagine - Chinese clones. These clones have tremendous frequency response, perfect square wave response and low THD. Today I have listened to the latest I've built. In quiescent state it has no sound whatsoever and has exciting sound indeed when connected to proper source.
I have found it by asking myself different question: if I were a Chinese businessman, which of available designs should I use in more expensive products, with fancy chassis. The answer was A60. I have asked myself rather than the echo chamber. I trusted my sound judgement and was right to do so.😀
And, by the way, which is your present project? You always have something interresting on the bench.
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I am working on two headphone amplifiers.
One is the famous Pass HPA-1:
Pass HPA-1, what do we know?
The other is the WHAMMY:
"WHAMMY" Pass DIY headphone amp guide
Both projects will take a couple of months.
One is the famous Pass HPA-1:
Pass HPA-1, what do we know?
The other is the WHAMMY:
"WHAMMY" Pass DIY headphone amp guide
Both projects will take a couple of months.