OK! so looks like there is significant interest again and not wanting to be outdone by Thomo, I too have been playing with a 63 again. I've striped out most of what I did to it previously including the DOS, mainly because I want to try and build in a much tidier way this time. One of my main frustrations was getting the board in and out once you have a few PSU's etc. Hopefully with this in mind, I will make it much easier to work on in the future. The original mains TX has gone along with the mains switch making space for the 80va Servo TX (only becuase the 50va was out of stock!!), display TX and one of the 9v TX's. I've also found that the little 7va 9v TX's fit nicely down the side of the transport, and on that note, I'm using a 67SE case as it is a little wider than the 63.
I started by noting all the points on the PCB that I would like to supply. The attached diagram is the start on 5V regulation. I think I worked out that I will need 12 (poss 14 if you seperate the digital supplies on the filter and servo) low noise regs inc one in the original position. I will remove the CPU and remote feeds an put them onto their own std 7805. This will mean only vrefs are on the main reg. Also, there is a track that needs cutting to separate the HF amp feed from the remote circuit. It looks like link U185 provides a feed to both areas. I will remove the supply leg of R505 and connect the reg for the HF amp to it. U185 will get a 7805 for the remote circuit.
The driver IC's will also each get their own regs and the DOS too bringing the total to 22 (hot on the heals of Brent!!)
Work is well underway, most of the TX have been sized up for mounting in the case and I've spent ages building up regs!!! I'll post some pics as I can.
I started by noting all the points on the PCB that I would like to supply. The attached diagram is the start on 5V regulation. I think I worked out that I will need 12 (poss 14 if you seperate the digital supplies on the filter and servo) low noise regs inc one in the original position. I will remove the CPU and remote feeds an put them onto their own std 7805. This will mean only vrefs are on the main reg. Also, there is a track that needs cutting to separate the HF amp feed from the remote circuit. It looks like link U185 provides a feed to both areas. I will remove the supply leg of R505 and connect the reg for the HF amp to it. U185 will get a 7805 for the remote circuit.
The driver IC's will also each get their own regs and the DOS too bringing the total to 22 (hot on the heals of Brent!!)
Work is well underway, most of the TX have been sized up for mounting in the case and I've spent ages building up regs!!! I'll post some pics as I can.
Attachments
7 5v regs in! 2 ready to fit, 2 more required then onto the driver IC's 
An externally hosted image should be here but it was not working when we last tested it.
Took a bit of scavenging but it's getting there. I want to get this right so there has been quite a bit in the planning. I even managed to fix the c2 to the board on fixed stand offs. There was just about enough space between the dac and decoder! I'll also need a couple more SI's, I have 10 but plan to use 12
I think I've made good use of the black gates I have. All off the analogue rails are using them but I can't source any large larger values now so no nice post reg 3300uf at the mo. I've also saved a basket on farnell for a complete silvered mica recap around the servo, hf and clocking circuits. Hopefully I'll also now be able to directly clock the decoder too (1st attempt failed as I didnt include the 10pF in the feed )
I really need to get to a point that I can check the work I've done! I think a few std regs on the CPU and remote sections and then i'll hook it all up
I think I've made good use of the black gates I have. All off the analogue rails are using them but I can't source any large larger values now so no nice post reg 3300uf at the mo. I've also saved a basket on farnell for a complete silvered mica recap around the servo, hf and clocking circuits. Hopefully I'll also now be able to directly clock the decoder too (1st attempt failed as I didnt include the 10pF in the feed
)I really need to get to a point that I can check the work I've done! I think a few std regs on the CPU and remote sections and then i'll hook it all up
You would not believe how many times i've been asked that. Its hard to say but working out how much is done each time on a 'upgrade through work' it's more like level 20. The costs get heavy for a customer as time is money. I would say £3000 to get it there, that includes weeks of labour lol
Simon you know what it sounds like so i'll not preach about where its at.
Brent
Simon you know what it sounds like so i'll not preach about where its at.
Brent
Hehe, it's good to see you put a figure on it though.
I know where it's at, and it is (obviously?!) pretty remarkable in its clarity, detail retrieval and separation of the musical layers or strands. Certainly in the context of the whole system, not like I've heard it substituted for another player but I suspect it's more than a large part of why it all sounds like that.
I know where it's at, and it is (obviously?!) pretty remarkable in its clarity, detail retrieval and separation of the musical layers or strands. Certainly in the context of the whole system, not like I've heard it substituted for another player but I suspect it's more than a large part of why it all sounds like that.
I'm aiming a little higher than that!!! I've already got 6 x 7va@9v for all the 5 v rails but I want more! There's also the Driver IC psu still to be done so thats another 6 regs on their own PSU and massive TX. I've not even started the output stage PSU yet!
The sarcasm went right over my head ealier
I've got a lot to try and live up to here, my 960 was sounding very good before I tried to build the offboard DAC. I'd poss say it was very very close to the limit on whats actually possible from the TDA. I absolutely realise that the compnents I'm fitting must be premium, I only want to do this once so I need to get it right 1st time!!
LOL. Do you think it will be -5.2 when it goes up in flames?
I'll be adding a few more psu's in later today. Will probably replace the SE tx with a KI toroid and use the original output windings for the Dac. That'll then free up two windings @12v for something else later on once all the additional psu's are in.
Lee.
I'll be adding a few more psu's in later today. Will probably replace the SE tx with a KI toroid and use the original output windings for the Dac. That'll then free up two windings @12v for something else later on once all the additional psu's are in.
Lee.