to second myleftear, try it if you have everything on hand. At worse, you find out you don't like it. Bass might be underdamped but might be your thing.
Will try
Thank you both! If the unique risk is the amp not sounding that great i think will give it a try. I read a post of 6l6 indicating that majority of time aca sounds better bridged. When i finished the two Monos, after the smoke test,i plugged each one singularly in stereo to check they worked. Just after i moved to mono parallel and i was surprised the volume was similar and control on bass slightly better only.
This morning i wake up and thought maybe parallell is not best for me and my system... The rest of the story you know. Cheers
Thank you both! If the unique risk is the amp not sounding that great i think will give it a try. I read a post of 6l6 indicating that majority of time aca sounds better bridged. When i finished the two Monos, after the smoke test,i plugged each one singularly in stereo to check they worked. Just after i moved to mono parallel and i was surprised the volume was similar and control on bass slightly better only.
This morning i wake up and thought maybe parallell is not best for me and my system... The rest of the story you know. Cheers
in parallel, the gain is the same, output impedance decreases. This makes more current available to control the speaker load. So the bass tightens up but there isn't more voltage to swing that current more.
What do you mean by "bridged"? Balanced mode? If so, this will provide a larger voltage swing but result in a larger output impedance. So more gain but less control. The bass may sound boomier.
I very much liked the spookiness of the ACAs in balanced mode but with the ported parallel driver design of the speakers I'm using, the bass was way too pronounced and very ill-defined. Not sure what speakers you're using but unless they present a highly capacitive load (like an ESL) the ACAs should operate with no harm to them.
The balanced mode of the ACAs gave me enough taste to go down the rabbit hole of attempting to build up some 1st Watt clones that can operate with authority in balanced mode. I liked the balanced ACA monoblocks that much.
What do you mean by "bridged"? Balanced mode? If so, this will provide a larger voltage swing but result in a larger output impedance. So more gain but less control. The bass may sound boomier.
I very much liked the spookiness of the ACAs in balanced mode but with the ported parallel driver design of the speakers I'm using, the bass was way too pronounced and very ill-defined. Not sure what speakers you're using but unless they present a highly capacitive load (like an ESL) the ACAs should operate with no harm to them.
The balanced mode of the ACAs gave me enough taste to go down the rabbit hole of attempting to build up some 1st Watt clones that can operate with authority in balanced mode. I liked the balanced ACA monoblocks that much.
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6sx7 thanxs speakers are 164 nomex
I posted the impedance and phase curve but they went up the pages, so you could not see it. I gave a try as mono bridged (rca input as per manual) and in fact bass became enveloping but list a bit of control as you said. Now back to parallell for a while. The bridged way was btw nice as no squelchy sound at turn on
But this does not drive the decision ultimately
I posted the impedance and phase curve but they went up the pages, so you could not see it. I gave a try as mono bridged (rca input as per manual) and in fact bass became enveloping but list a bit of control as you said. Now back to parallell for a while. The bridged way was btw nice as no squelchy sound at turn on
But this does not drive the decision ultimately
It is about the enjoyment, isn't it?
I have friends that always ask what scotch is good. I always reply "the one you enjoy."
Good times!
I would be grateful for confirmation on the following schematics " that I do not require the resistor modification" on the ACA clone schematic. I have attached the ACA clone schematic and the ACA V1.6 schematic. My brain says that they are equivalent in the area of R116 vs R15. See attached
Thanks
MM
View attachment ACA-AMP_V1_SCH.pdf
Thanks
MM
View attachment ACA-AMP_V1_SCH.pdf
Great guy.
I recall that in late '72 Bob paid a visit to ESS. There are photos of him
sitting on their amplifier assembly line, putting an ESS 500 together.
ACA no sound here are measurements
Hi guys, I can't find the post I just submitted. I completed my second ACA to hear them in mono but not getting any sound. I may have a solder bridge on the RCA connectors so I pulled them and have the RCA wires free and not touching anything. Here is what I am getting from step 56 Trouble shooting. I pulled the boards and can not see any solder bridges. Help please.
Right board
Q1 a 2mv
Q1 b. .3mv
Q1 c. 18.05
Q2 109mv
Q2 b 20mv but moving
Q2 C .4mv
Left board
Q1 a.1 mv
Q1 b.3 mv
Q1 c 17.96 volts
Q2 a. 119mv
Q2 b 23.99 volts
Q2 c .3mv
Any thoughts?
Hi guys, I can't find the post I just submitted. I completed my second ACA to hear them in mono but not getting any sound. I may have a solder bridge on the RCA connectors so I pulled them and have the RCA wires free and not touching anything. Here is what I am getting from step 56 Trouble shooting. I pulled the boards and can not see any solder bridges. Help please.
Right board
Q1 a 2mv
Q1 b. .3mv
Q1 c. 18.05
Q2 109mv
Q2 b 20mv but moving
Q2 C .4mv
Left board
Q1 a.1 mv
Q1 b.3 mv
Q1 c 17.96 volts
Q2 a. 119mv
Q2 b 23.99 volts
Q2 c .3mv
Any thoughts?
ACA no sound
I am confused on how to trouble shoot. I am looking at the chart from step 56 showing resistance checks. Do I have power on or do I measure without any power? Do I ground the black lead and use the red one to touch the resistor leads to check Ohms?
I also noticed my new ACA kit came with a brown capacitor at C2 where the older kit that works, has a black capacitor at C2.
Thanks
I am confused on how to trouble shoot. I am looking at the chart from step 56 showing resistance checks. Do I have power on or do I measure without any power? Do I ground the black lead and use the red one to touch the resistor leads to check Ohms?
I also noticed my new ACA kit came with a brown capacitor at C2 where the older kit that works, has a black capacitor at C2.
Thanks
Resistance checks are with power off, no speakers or inputs connected.
Voltage checks are with power on (no speakers or inputs connected).
Negative -Ve black to GND and positive +ve Red to test point. The range settings are written on the trouble shooting sheets.
Maybe look at some digital meter tutorials on YouTube etc.
Make sure components are in the correct positions and right way round etc. It might help if you post good pictures of your build.
Do not worry about capacitor colours.
Alan
Voltage checks are with power on (no speakers or inputs connected).
Negative -Ve black to GND and positive +ve Red to test point. The range settings are written on the trouble shooting sheets.
Maybe look at some digital meter tutorials on YouTube etc.
Make sure components are in the correct positions and right way round etc. It might help if you post good pictures of your build.
Do not worry about capacitor colours.
Alan