Semantics Rudi but he has two completely seperate mono amps (transformers, rectifiers & amplifier boards) in one single chassis - so the amp boards are by definition mono in that each PCB only handles one channel.
I know, I know, but I had the boards and I thought I'd give the best I could for the boards after you had taken the trouble and time to lay them out so well 🙂
Just noticed that the transformers get a little hot after about 30 minutes or so, are they are supposed to be for another project....
I saw that the original ACA stereo amp could be configured as a mono block (bridged mono as in that doc you attached), I was just wondering in the same wiring scheme could be used for your PCB.
And I have an F5T. It doesn't quite do what my KSA50 clone can do, but this little ACA you have designed is very, very sweet - I love the form factor and the sq is impressive.
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Gentlemen, there has not been any change concerning this small groupbuy in the past days.
I have therefore decided and ordered the PCBs already this morning.
It is therefore too late to place a new order.
Find attached the final order - EXCEL sheet.
I have told you about plans to use the ACAs together with a pair of SYMASYMs in a BI-amping / active (?)
scheme to drive speakers with an impedance of < 8 Ohms.
I have 3 pairs of the SYMASYM , shown in the image below, left.
Is anybody of you interested to have a pair? A pair of SYMASYM PCBs costs 15€.
Best regards - Rudi_Ratlos
I have therefore decided and ordered the PCBs already this morning.
It is therefore too late to place a new order.
Find attached the final order - EXCEL sheet.
I have told you about plans to use the ACAs together with a pair of SYMASYMs in a BI-amping / active (?)
scheme to drive speakers with an impedance of < 8 Ohms.
I have 3 pairs of the SYMASYM , shown in the image below, left.
Is anybody of you interested to have a pair? A pair of SYMASYM PCBs costs 15€.
Best regards - Rudi_Ratlos
Attachments
I would love to get a pair of the SYMASYM boards. Let me know what the additional shipping costs are to the US. Thanks!
Peter, since the weight of the PCBs (2 x ACA plus 2 x SYMASYM plus a green PCB ), MPC resistors and Audio-CD does not exceed 500 gr,
I will include the SYMASYM PCBs in your ACA letter and you do not have additional shipping costs.
So: if you like to have the SYMASM PCBs: please transfer 15€ to my PAYPAL account.
Best regards - Rudi_Ratlos
P.S.: To you and Kristian: the small green PCB is "for nothing".
It is a very accurate and low-noise " dual LT3042 PSU" to be used (if you like to) as frontend-PSU for your SYMASYM.
I will send you its documentation as well.
I will include the SYMASYM PCBs in your ACA letter and you do not have additional shipping costs.
So: if you like to have the SYMASM PCBs: please transfer 15€ to my PAYPAL account.
Best regards - Rudi_Ratlos
P.S.: To you and Kristian: the small green PCB is "for nothing".
It is a very accurate and low-noise " dual LT3042 PSU" to be used (if you like to) as frontend-PSU for your SYMASYM.
I will send you its documentation as well.
Attachments
Thanks Rudi! 
order update
Rudi; I'm wondering if you could add an order of the resistors to my board order? If yes what is the price U.S. dollars?
Rudi; I'm wondering if you could add an order of the resistors to my board order? If yes what is the price U.S. dollars?
For anyone in the US that needs .47 and .22 MPC71 resistors. I can get them locally and can help ship.
The .56 I can’t so Rudi has been helping me get those.
The .56 I can’t so Rudi has been helping me get those.
....aaaaah.....i am too late
if possible put me on a waiting list please...thx
chermann 4pcb = 2 amps
if possible put me on a waiting list please...thx
chermann 4pcb = 2 amps
The information on "needing" LT4320 is incomplete IMHO. No one "needs" the amplifier in the same sense either.
The ideal rectifier has way lower Uf and resulting rectified/filtered DC voltage will be higher and losses/heat will be lower. Since the ideal rectifier starts to conduct earlier wave form looks slightly better and transformer loading is slightly more elegant. Regardless of whatever technical reasons/beliefs/preferences, in my experiments with other devices that consume way less current than 2A the difference sonically was so interesting I updated nearly all devices to LT4320 rectifiers. If it wouldn't be that I could choose lower secondary voltages of transforers when using LT4320 etc. I would do it just because it sounds better. Don't ask me why, as much as I would like to know myself I haven't figured out why the difference is there. To be honest I thought them to be overly complex compared to the good old diode bridges. I also use Saligny rectifiers and results are OK too.
All situations are with well measuring, previously already good sounding HiFi devices.
The ideal rectifier has way lower Uf and resulting rectified/filtered DC voltage will be higher and losses/heat will be lower. Since the ideal rectifier starts to conduct earlier wave form looks slightly better and transformer loading is slightly more elegant. Regardless of whatever technical reasons/beliefs/preferences, in my experiments with other devices that consume way less current than 2A the difference sonically was so interesting I updated nearly all devices to LT4320 rectifiers. If it wouldn't be that I could choose lower secondary voltages of transforers when using LT4320 etc. I would do it just because it sounds better. Don't ask me why, as much as I would like to know myself I haven't figured out why the difference is there. To be honest I thought them to be overly complex compared to the good old diode bridges. I also use Saligny rectifiers and results are OK too.
All situations are with well measuring, previously already good sounding HiFi devices.
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If I have time this week I can create a BOM for mouser. The only parts I couldn’t source from mouser were the MPC71/74 Futaba resistors, but my local electronics store has .22 and .47.
Gentlemen, I have received the "Premium ACA PCBs" this morning (image 1).
Concerning the post of "Jean-Paul" (post #194) in this/my Premium_ACA – thread a couple of posts before:
I have appreciated the posts of "Jean-Paul" in this forum in the past and thought of him to be a „High-Ender“.
He is definitely no more – in my opinion - after his post.
I have looked through all of my „Premium-ACA“ EXCEL – buyer sheets.
"Jean-Paul" has never ordered/bought a PCB-pair of them.
So: what is he talking about?
I doubt that he has even taken a look on the schematics on this (my) „Premium – ACA“.
He would have noticed – in this case - that my ACA – layout contains a „high sophisticated“, regulated (!) CAP-Mx PSU,
which does an undoubtedly good job, not regarding „who is doing the rectification“.
There is definitely no reason to optimize anything concerning „my Premium ACA – design“.
I would be very happy, if Jean-Paul apologizes to have intruded this thread with his ears“ - Rudi_Ratlos
Concerning the post of "Jean-Paul" (post #194) in this/my Premium_ACA – thread a couple of posts before:
I have appreciated the posts of "Jean-Paul" in this forum in the past and thought of him to be a „High-Ender“.
He is definitely no more – in my opinion - after his post.
I have looked through all of my „Premium-ACA“ EXCEL – buyer sheets.
"Jean-Paul" has never ordered/bought a PCB-pair of them.
So: what is he talking about?
I doubt that he has even taken a look on the schematics on this (my) „Premium – ACA“.
He would have noticed – in this case - that my ACA – layout contains a „high sophisticated“, regulated (!) CAP-Mx PSU,
which does an undoubtedly good job, not regarding „who is doing the rectification“.
There is definitely no reason to optimize anything concerning „my Premium ACA – design“.
I would be very happy, if Jean-Paul apologizes to have intruded this thread with his ears“ - Rudi_Ratlos
Attachments
Hi dear, are gerbers for this excellent ACA pcb available for share?
If not, are you shelling boards?
Regards.
Thimios
If not, are you shelling boards?
Regards.
Thimios
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