Hi Neel,
That is strange?
First thing to look at is why there is an open circuit through R1,2,3 and 4 on the faulty side?
If you look at the circuit diagram you will see Q1 D and Q2 S are 'joined together' through R1 to R4 and should read very close in resistance (0.57 ohms different) and about 0.8 to 0.9 volts different in voltage.
Alan
I know you have different boards, but on the ACA 1.6 boards Q1 D and Q3 e are on the same track so have to be the same resistance and voltage. Yours are different, so likely you have a fault with the track or soldering going to Q1 where Q3 e, R15, R3 and R4 join it?
Alan
Hi Alan,
Thank you, The odd thing is it worked perfectly until two weeks ago. The component placement is exactly like on the 1.6 boards, i just made it 'single layer'.
I will start with checking the copper layers and the soldering.
to be continued....
Bummer.
Nothing but a shame that an honest man has to suffer such deprivations because the misdeeds of others raise so much suspicion.
Thanks, I'm trying to fight off the urge to build a 300B to find out for myself.
I only know people with parallel 300B, and 300B "X" tubes that cost $900 to $1200 a pair or more.
Yes, the MoFo is fantastic.
Thanks for the info. Feel free to PM me as to not take up space here.
thanks,
Vince
I only know people with parallel 300B, and 300B "X" tubes that cost $900 to $1200 a pair or more.
Yes, the MoFo is fantastic.
Thanks for the info. Feel free to PM me as to not take up space here.
thanks,
Vince
It's been years since I've built / heard a 300B amp, and a lot of the "sound" of said amplifier is dependent on the driver circuit. And the speakers - because of the high output impedance - being used.
They definitely are different beasts. Old me would have preferred the "tubey-ness" of the 300B. The current me prefers the ACA (or - now - the Aleph J) since it imparts less of its character on the sound.
They definitely are different beasts. Old me would have preferred the "tubey-ness" of the 300B. The current me prefers the ACA (or - now - the Aleph J) since it imparts less of its character on the sound.
No experience in my place with a 300b - although I've heard a few at audio shows years back.
There is a 2A3 amp that gets used with the same speakers the amp camp amp is currently driving. The 2A3 amp is sweeter sounding and somewhat lush compared to the ACA. The ACA is cleaner, has better bass definition and about 3 times the power. I can't say which one is better as they are both very nice.
I'd describe the ACA sonics as being somewhere between a traditional solid state amp and a pretty tube amp. The ACA doesn't have the sweetness of some tube amps but it does seem to have the 2nd order harmonic thing going on.
Both amps excel at sounding good at lower levels which makes them my two favorite amps at the moment. Most of the other amps I've owned (or own) require some juice to open them up and sound good. The ACA and 2A3 strut their stuff at reasonable levels and that makes the listening sessions go longer and with far less wear and tear on my ears.
There is a 2A3 amp that gets used with the same speakers the amp camp amp is currently driving. The 2A3 amp is sweeter sounding and somewhat lush compared to the ACA. The ACA is cleaner, has better bass definition and about 3 times the power. I can't say which one is better as they are both very nice.
I'd describe the ACA sonics as being somewhere between a traditional solid state amp and a pretty tube amp. The ACA doesn't have the sweetness of some tube amps but it does seem to have the 2nd order harmonic thing going on.
Both amps excel at sounding good at lower levels which makes them my two favorite amps at the moment. Most of the other amps I've owned (or own) require some juice to open them up and sound good. The ACA and 2A3 strut their stuff at reasonable levels and that makes the listening sessions go longer and with far less wear and tear on my ears.
I like the sound discussion so far but think that a lot of the sound quality is not only due to the ACA or final amp, but to some variable degree to all of the components used from source to speakers. The sound of the ACA will be different when different speakers are used, and the same can be said for the input coming from the DAC, preamps, and even the linkages used plus the sonic quality of the room used for playing the sound.
My thoughts exactly. It would be helpful if at least preamp and speakers are also mentioned when sound impressions are posted.
Vince, are you not interested in the details on the ACA that Tony mentioned to build your very own ACA V3.00B? The use of a power Jfet or SIT as gain device could be a factor.
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If you mean "Would Stanislav prefer the sound of a modified ACA using a low voltage, high current FET, like IRFP044, or IRFZ40 and so on?" , nobody can answer the question but you.
Fortunately it's not a difficult experiment to perform.
This discussion of a high current, low voltage ACA using high current FETs will result in a circuit that may indeed sound wonderful, but will not be an ACA. It should be remembered that one of the aims of Mr. Pass is to foster experimentation, so please have a go at it but remember that the result is not an ACA. It could be called an HC ACA though.
Let me think about this outloud for a second. You build your ACA and want more of the same or similar or better sound. The standard path is to build something else like an Aleph J. The less, more experimental, path is to modify the ACA into something totally different like a high current amp instead of a voltage amp. If this is what you wish to do, I would suggest buying a set of additional blank PCBs to play with and leave your ACA (or ACAs) alone. You can get your own parts. When you are done you can compare them side by side in your own system and let us all know how the sound is differen and how you modified the circuit.
Let me think about this outloud for a second. You build your ACA and want more of the same or similar or better sound. The standard path is to build something else like an Aleph J. The less, more experimental, path is to modify the ACA into something totally different like a high current amp instead of a voltage amp. If this is what you wish to do, I would suggest buying a set of additional blank PCBs to play with and leave your ACA (or ACAs) alone. You can get your own parts. When you are done you can compare them side by side in your own system and let us all know how the sound is differen and how you modified the circuit.