Audio Research Ref: CD8

hello Tonywinsc , let us make one thing clear , the big tube is NOT a rectifier tube and also the 6h30 tube in the powersupply . The are used as stabilisation . From 120V AC transformer current is rectified by solid rectifiers . So there will be no long wires under the board. Same as the upgrade of the CD7 .

But I'm compelled to say that I am a bit underwhelmed at the layout of the PCB inside the CD8. I know that sound is the ultimate goal and I don't mean to dis your nice player. It's just that the tube analog section doesn't seem isolated from both the PS sections or digital sections.

The DAC chip is not a problem. In most players it is placed very close to the analog stage. The "dirty part" is the display, transport and its servo board, and those are situated as far as possible from the analog section for an integrated player. 6550 tube, as noted before, in not a rectifier tube. ARC had to stuff a lot of parts inside the box, and taking that into consideration, they did a remarkable job.

Then why the bank of electrolytic capacitors next to the big tube?

Hello Tonywinsc , the electrolytic caps are needed to smooth the direct current after being alternate current to be changed by solid rectifiers .ARC always is famous by making very good powersections in their gear.Its the most important part of the design. You will notice there is no sign of humm in whatever gear of them.

I just sent my CD7 away for the upgrade. I think my player had the previous "lifeless" upgrade that was referred to above where a raised board was installed to hold the two 6H30 tubes. Perhaps a version 2 from the original. If this is the case, I cannot wait to hear the latest version and the associated improvements on an already great player. I will post my findings when it returns. Better sound and more reliable? Who could ask for more from a great company like Audio Research. I, for one, say continuous improvement is a good thing....