Converting A&R A60 to AP
- Thread starter Mistrale
- Start date
Operajulian
Julian
Hi there:
A&R made a small special circuit board that was mounted by the tape input. With "flying leads" to other locations on the main pcb.
Do you have one of those ?
The circuit layout is on the service manual but I don't recommend making your own.
A&R made a small special circuit board that was mounted by the tape input. With "flying leads" to other locations on the main pcb.
Do you have one of those ?
The circuit layout is on the service manual but I don't recommend making your own.
Operajulian
Julian
I took a look inside one of my A60 AP.
If you manage to track down an A&R daughter board. These are the connections.
There is a 6 colour ribbon cable from the daughter board.
Black goes to the main pcb to a point marked "E" just beside C122.
Remove capacitors C22 and C122 and solder in the following four wires.
C22 - Yellow goes to +ve, Orange to -ve
C122 - Red goes to +ve, Brown to -ve
The remaining Green goes to the point marked with a + between Q106 and TP1.
Up by the Din inputs you also need to solder a link across the two dashed lines marked as A.P.
Good luck.
Julian
If you manage to track down an A&R daughter board. These are the connections.
There is a 6 colour ribbon cable from the daughter board.
Black goes to the main pcb to a point marked "E" just beside C122.
Remove capacitors C22 and C122 and solder in the following four wires.
C22 - Yellow goes to +ve, Orange to -ve
C122 - Red goes to +ve, Brown to -ve
The remaining Green goes to the point marked with a + between Q106 and TP1.
Up by the Din inputs you also need to solder a link across the two dashed lines marked as A.P.
Good luck.
Julian
Julian, I can't see a problem with making the daughter board on Veroboard or similar, but don't know where the differently coloured leads come from on it. (I once rebuilt two NAC42 circuits on such board.)
Would you mind clarifying that, as you have for their destinations on the main board ? BTW the A60 turned out not to be an AP.
Many TIA
Keith
Would you mind clarifying that, as you have for their destinations on the main board ? BTW the A60 turned out not to be an AP.
Many TIA
Keith
Operajulian
Julian
As luck would have it - sorry it is not an AP. The last A60 I bought off ebay for repair/fixing turned out to be an AP version without the shorting plug 
I scored a working AP instead.
From what I make out. Green is +ve to the daughter board, Yellow is from +ve of C3 to +ve of C22 on main pcb, Red to +ve of C122. Black DIN pin 2 to Ground or E on main board . I'm guessing where orange and brown originate on daughter pcb.
Sen me a PM with your email and I will send a photo.
Julian
I scored a working AP instead.From what I make out. Green is +ve to the daughter board, Yellow is from +ve of C3 to +ve of C22 on main pcb, Red to +ve of C122. Black DIN pin 2 to Ground or E on main board . I'm guessing where orange and brown originate on daughter pcb.
Sen me a PM with your email and I will send a photo.
Julian
On looking again at the circuit diagrams I can't see why the pre-amp needs more than C22(122) if it's connected only to its own power amp when in integrated mode, i.e. with a shorting plug fitted.
I'd really like one of the experts to explain what the pre-amp side of the AP board does and whether the pre-amp can manage without it in the circs intended - I just want to use the power amp section with a Denon AVD2000 DAC / pre-amp or the whole A60 in integrated mode.
I'd really like one of the experts to explain what the pre-amp side of the AP board does and whether the pre-amp can manage without it in the circs intended - I just want to use the power amp section with a Denon AVD2000 DAC / pre-amp or the whole A60 in integrated mode.
If anyone's interested I'm reporting as requested by Opera Star (thanks for help, Julian).
I converted one of my A60s to AP, but the power amp on its own, downstream from a DAC/"pre-amp" (actually a DAC/attenuator, as it turns out) isn't powerful enough to drive speakers.
I'm therefore bi-amping with one A60 (pre + power) per speaker, and this is a distinct improvement on one A60 driving two speakers.
Thoughts now turn to replacing R50/150, wiring out tone controls, etc.
I converted one of my A60s to AP, but the power amp on its own, downstream from a DAC/"pre-amp" (actually a DAC/attenuator, as it turns out) isn't powerful enough to drive speakers.
I'm therefore bi-amping with one A60 (pre + power) per speaker, and this is a distinct improvement on one A60 driving two speakers.
Thoughts now turn to replacing R50/150, wiring out tone controls, etc.
rhgbristol
pfm Member
The Ap60 is well worth seeking out, I have one used as a pre-amp in conjunction with Linn Lk280/spark power amps.
With its tone controls and effortless power, it's one of the most exciting sounding amps I've owned.
The pre-amp with tone controls, and decent quality make it quite a rare unit.
With its tone controls and effortless power, it's one of the most exciting sounding amps I've owned.
The pre-amp with tone controls, and decent quality make it quite a rare unit.
RHG, sorry for the delay in thanking you for your input - much appreciated.
The A60 doesn't seem to struggle, although using one per speaker helps in my case.
Ironically, being of the minimalist school, I'm about to post on bypassing the tone and balance controls !
The A60 doesn't seem to struggle, although using one per speaker helps in my case.
Ironically, being of the minimalist school, I'm about to post on bypassing the tone and balance controls !
rhgbristol
pfm Member
For fear of sparking the debate about tone controls, I must admit I do use them, in my second system, to compensate for such wide variations in recordings.
I often wish I had the a60plus in my main active isobarik system as the preamp instead of my linn kairn!
Shock, horror, I know!!
I often wish I had the a60plus in my main active isobarik system as the preamp instead of my linn kairn!
Shock, horror, I know!!
Oh dear, RHG, I fear you may be ostracised on both counts !
As for the debate, after I had posted on bypassing them I saw that OperaJulian had found it made no audible difference on A60s, but must confess I left my post up to see if anyone else would comment.
And as for Kairn, why not try the A60 !
As for the debate, after I had posted on bypassing them I saw that OperaJulian had found it made no audible difference on A60s, but must confess I left my post up to see if anyone else would comment.
And as for Kairn, why not try the A60
!
Erskine Ears
pfm Member
Hi Mistale, I'm interested in knowing more about your a60 per speaker setup. Are these amps bridgeable?
Operajulian
Julian
They don't come up for sale very often but here as of Feb 25th 2020 - there is one ( with a tuner ) on the Bay thing.
http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=392691437361
This site contains affiliate links for which pink fish media may be compensated.
graham-r
pfm Member
Julian
My first post on PF for a long time - I have just finished (as an exercise) converting the standard A60 PA circuit (issue 8) to a PCB layout with a view to building some modified versions for a car amp at a later date.
The question is to do with the AP/C22(122) - on the AP amp does C22/122 actually exist ?
Many thanks
Graham
My first post on PF for a long time - I have just finished (as an exercise) converting the standard A60 PA circuit (issue 8) to a PCB layout with a view to building some modified versions for a car amp at a later date.
The question is to do with the AP/C22(122) - on the AP amp does C22/122 actually exist ?
Many thanks
Graham
Last edited:
Operajulian
Julian
Hi Graham
The C22 and C122 from the A60 main pcb are removed as per the earlier post.
Remove capacitors C22 and C122 and solder in the following four wires.
C22 - Yellow goes to +ve, Orange to -ve
C122 - Red goes to +ve, Brown to -ve
The remaining Green goes to the point marked with a + between Q106 and TP1.
The C22 and C122 from the A60 main pcb are removed as per the earlier post.
Remove capacitors C22 and C122 and solder in the following four wires.
C22 - Yellow goes to +ve, Orange to -ve
C122 - Red goes to +ve, Brown to -ve
The remaining Green goes to the point marked with a + between Q106 and TP1.
graham-r
pfm Member
Thanks Julian
I don't have an AP amp so am just relying on the service manual.
The service manual is a little vague in this area as it shows a combination of A60 & A60AP on the same (pre-amp & tone control) diagram, on second thoughts it doesn't really matter that much as the AP version of the PA can be connected as shown - i.e. before C22/122, the standard amp after the capacitor
I've finished the KiCAD design of the standard issue8 mono PA (which I won't actually be building), I'm going to do another version with all the recommended mods with a view to making it suitable for a car as well as domestic.
I will put the completed project up on Github if anyone is interested.
I don't have an AP amp so am just relying on the service manual.
The service manual is a little vague in this area as it shows a combination of A60 & A60AP on the same (pre-amp & tone control) diagram, on second thoughts it doesn't really matter that much as the AP version of the PA can be connected as shown - i.e. before C22/122, the standard amp after the capacitor
I've finished the KiCAD design of the standard issue8 mono PA (which I won't actually be building), I'm going to do another version with all the recommended mods with a view to making it suitable for a car as well as domestic.
I will put the completed project up on Github if anyone is interested.
graham-r
pfm Member
For anyone interested in an A&R A60 or A60AP Power amp - there is a KICAD project in github
https://github.com/graham-r/kiCAD_AR_A60
https://github.com/graham-r/kiCAD_AR_A60