Audio Research Ref: CD8

I think 6550 is more powerful than a 5881 (that is a smaller version of the 6L6), This tubes are being used in the PS so they are not in the path of sound, but as a part in the PS. As long as there is enough power for the audio circuits I don't think they will make any change in the sound result. But the malfunction of then (like what was happening with the two 6H30) will affect sound.

Many people here saying CD8 is better than CD7, but how manny of them had a PS CD7 fault and don't know about it. What people is saying is that a CD7 with the last update and CD8 the difference in sound is not big.

Many people here saying CD8 is better than CD7, but how manny of them had a PS CD7 fault and don't know about it.

I'm pretty sure my did not have this problem after ~ 800 hours (my came with the upgrade 6H30 board installed from the factory). Not long before I sold the player, I have put a brand new set of tubes (all 7), just to see how much the original tubes deteriorated with time, only to find out no real difference in sound quality between the two sets.

So, as far as I'm concerned, the CD-7 was one of the best, if not THE best CDP I have owned so far - both sound quality and reliability wise.

I found the minet CD7 sometimes lifeless and sound diffrent each time I turn it on, only after 3-4 hour of use the sound goes better. The sound is very far far away from the one when he came out from from box prior to the upgrade. Let's see if I will get my sound back after this new upgrade.

Nice pix of the inside of the player. 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. Is the analog section that robust? And the position of the large rectifier tube seems a bit odd. I wonder how the wires are routed underneath the PCB- going all the way across the PCB from the 120VAC Tranformer to the rectifier tube. I have and appreciate my ARC gear so don't take me as being mean spirited. Others with more electronics knowledge than me may have some ideas for some quick and easy tweaks for your player.

Anyone cares to post images of his upgraded CD-7 ? I wonder how the managed to fit the 5881 tube inside the CD-7, which has a bit different PCB layout.