ARC PH5-Tube info. and suggestions

I'm pretty vague on the PH5 topology, but am pretty sure there are 2 tubes per channel - either the manual or ARC can tell you which in the layout go to which channel. Matching would happen between each pair, not necessarily across all four. If you can get 4 matched, that is great because eventually one will go and you can use the singleton with either of the remaining pair - but, not required, and its typically easier to find two match pairs than it is a quiet matching quad. All should be of the same type, that is all 7308 or all 6922, etc. It is also fine to have a mix of brands within a pair, which gives more opportunity for 'tuning' the sound to your liking.

Tim,
Thanks. Question: Do the 4 tubes all need to be matched pairs?

Easy to say and do if your'e treble isn't too hot! But if it is and it ruins the listening experience one has no choice to search for a better sound unless cotton in the ears is considered a worthwhile upgrade.

I have used the PH 5 for many months. The tubes that ARC uses are the best available for the job that can be gotten, either by the manufacturer or the end user, that will consistently meet known criteria. I have Bugle Boys and Orange Globes and have never been tempted to pop them in. I would rather just sit back and spin records.

I have used a PH7 in my system and done a bit tube rolling with it. The stock Sovteks tend to be quiet but they can sound a bit mechanical vs NOS. The whole 6DJ8/6922/7308 family is open to you and what to use comes down to personal preference. A reasonable 'middle of the road' place to start might be 7308 Amperex Orange globes. I've also had nice results from using 1 Valvo + 1 Siemens 7308 per channel, also 6DJ8 Telefunkens. Matched pairs (3-5%) for each channel will give better results, but super tight matching (1-2%) is not absolutely required. Most importantly, you'll want whatever you choose to be *quiet* with no or minimal microphonics. Have fun tube rolling your PH5!

Tim