Yes, I removed the grille. The amp comes with a t-handle screwdriver for removing the screws. Make sure the screwdriver is magnetized so you don't drop the screws. The Sophia tubes are a bit 'fatter' than other 6SL or SN 7's. The front pair (SL7's) have about a millimeter clearance between...

Quad isn't going to put high-end tubes in a $1,599 amp.

Find a Phillips/Mullard rectifier (UK plant, late 1960's).... then look for Sophia Electric 6 SN and SL 7's. Forget tube rolling. Get the Sophias. Unless you want to buy my RCA's and Heintz & Kaufmans, and etc. Then, replace the fuse.

I've got a PA-One (Serial ......0002) and have done tons of tube rolling... RCA Red Base, Heintz-Kaufman, Sylvania, ADZAM, etc. Finally settled on Phillips/Mullard rectifier (square getter) and Sophia Electric for the SN 6's and 7's. Hi_Fi Tuning fuse and etc. Pushing HiFiMan HE-1000 V2's...

Also using a AudioQuest Edison power outlet (the receptacle in the wall).

I'm using an IsoTek Sirius power conditioner. Nice improvement.

If you want to play 'tube rolling' I have a collection I'm willing to part with. RCA Red-base, Heintz-Kaufman (essentially a red-base RCA... in fact they had a patent encroachment suit in 1942, I think), ADZAM (Mazda spelled backwards), Sylvania's , etc... Think the Adzam (or Sylvania) were...

One more trick to help the sound, and this one shouldn't cost you anything ! This often helps, particularly if you have an older home. Tighten all the wire connections at your power panel. Jacketed wires come into the panel, and the last half-inch or so is stripped and pinch-connected with a...

I found the Phillips/Mullard 6CA4 / EZ81 rectifier at a shop in California. They're $75 now. I bought four or five of them when they were $50... from the same shop. The price increase suggests they're becoming rare. https://www.upscaleaudio.com/products/philips-miniwatt-6ca4-ez81 "Philips...

One more thing... Although the Quad accepts XLR or balanced cabling, the internal circuitry isn't balanced, and I believe the Quad's XLR input is grounded. A friend had a major problem with this. He picked up a hum in his system when he used the Quad's balanced inputs. My integrated amp...

My Quad has a sticker above the on/off switch and tells voltage, fuse, etc. Mine is set-up for US power. MusicDirect had the fuse, but Amazon had it for a lower price. If you do some searching you can probably sink a couple hundred bucks in the fuse. As with any of this stuff, you'll need to...

Mine came set-up for USA power. Hey, there's another trick you can do for the Quad... I installed a HiFiTuning fuse. It was about $60 from Amazon. There's a little drawer on back of the Quad. Pull that out and swap fuses. I think there's a spare in there... which I thought was a pretty...

I didn't look at any other headphone amps. My soundshop guy saw and heard it at a CES convention and recommended it. I told him to get it. I had to wait a little while, but one day it arrived. A good friend had a top-of-the-line Sennheiser. I shared the Quad... installed in his system. He...

Just to tease you.... my Quad is serial number xxxxxx0002. Got it before there was an authorized US dealer.