Arcam Alpha mods

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Haha, I'm taking my time as I've not had the player apart in months and needed to re-familiarise myself with things.

C210 and C214 are coming out as they're unused decoupling for the standard output stage. They'll clear a bit more room for one of the big new caps.

R201 and R202 (12R resistors) are coming out / being shorted as they filter psu noise/ripple and with just one big smoother per rail it will be better without them.

I may place wire under LK3 and LK7 to reduce ground impedance a tiny bit on those links.

I toyed with the idea of feeding the +-5V regs directly from the raw supplies rather than from the +-15V regs as Arcam did it but I think I'll leave that alone for now and gauge the improvement from the new caps and resistor shorting.
 
Oh wow guys, this is amazing. I've rarely (if ever) heard such an improvement from top to bottom on every sonic aspect a reviewer could dream up!

I did do the ground and resistor jumpers, which probably was a part of it. Clearly, though, these caps are wonderful as smoothers in this position.

I've only listened to Jennifer Warnes so far and it's so smooth, detailed & open with deeper and more tuneful, detailed bass. The top end is more controlled and the whole soundscape has opened out.
 
Why clear the deck?

The reason I cleared the output stage is actually not for the space.

All the components are still in the circuit even if they are not in the signal path. I know it sounds strange, but all aspects of sound quality improved by getting these parts off board even though they were bypassed.
 
Here are the holes are wires I had to put on the PCB to get those big caps in place.
 

Attachments

  • HolesNWires.jpg
    HolesNWires.jpg
    152.5 KB · Views: 244
  • UnderPCB.jpg
    UnderPCB.jpg
    176.4 KB · Views: 234
To not have to remove the PCB again (means de-soldering clock and signal feeds from the DAC pins) I wound the cap out of the way and glued it down with hot-melt glue.

It's not perfect, needs a bit of tweeking but the tray just about shuts!
 

Attachments

  • NewPosition1.jpg
    NewPosition1.jpg
    155.5 KB · Views: 233
  • NewPosition2.jpg
    NewPosition2.jpg
    175.6 KB · Views: 228
Cor - that's it then - I'm off downstairs to rip it all open again - sh.. the wife will kill me - I've already lost two hours doing something else to it today - pah !!!

I've no room at all inside the box so I'm going to have to bolt the caps to the back panel for now.
It won't hurt doing that - and you just proved it - how glad am I ? :D

Pics already printed off........bye...........
 
I've not decided exactly, I just felt like doing it to use up some caps which are just old pulls. I might use it for smoothing my digital filter power supply, or the decoder, everything else has decent modern caps or is in the player where space is limited. This will be going off-board. Should only be about 9400uF, but the impedance will be pretty low with it being 20 caps in parallel.
 
Last edited:
Well, after all the excitement of the big caps job you did I dashed off to do my version, albeit with 2 half decent 6800 uf caps - they will fit perfectly where the 6 x 1000's were.

Stripped it down, did the links as you described and found I didn't have enough solder to finish it off !! :mad:

I can't use the exact words here - but you can probably guess.

So, tomorrow it is then :rolleyes:
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.