Very wise! I think there might be an element of liability about any electrical equipment in terms of interference it produces or being a potential fire hazard. aka Legendary Collectibles :) Yes!

Don't get into electric guitars then, those 12AX7 prices - damn!

I don't know, Tokyo guys are on a whole other level: https://www.wsj.com/articles/a-gift-for-music-lovers-who-have-it-all-a-personal-utility-pole-1471189463

Thank you for taking a moment to list all of them. Yes, I have been buying some from Hifi Collective. Unfortunately, all of these places are capitalising on the dwindling supply to various degrees of greediness. No hate, though! It's a fair game and I would do the same. There was a time...

Is there a good source for them? Mouser doesn't stock many values.

Interesting, thank you - not super-cheap but affordable.

@L0rdGwyn another noob question if you don't mind: when ordering PCBs are you forced to buy a small (e.g. 50) batch or do you have a way of getting just a few?

@bcowen @Paladin79 any advice on "healing" microphonic tubes, if that's even possible (without lab equipment)? Considering getting some of those silicon rings.

I would say they uglier something looks the likelier that it was made for the military :).

Transformer-like low hum - could be EMI, could be microphonics, could be a ground loop.

I clearly said "EMI" not "RFI".

Could not find any cheap double-EMI-shielded cables. Plenty of double-shielded with the useless foil.

I did not request anything specific in terms of vol pot to be honest. I had a look at one of gut photos and it says "ALPS JAPAN 049G 10KA x 2". I guess "10KA x 2" means it's a stereo 10kOhm with an audio taper, and perhaps "049G" is some manufacturing date code as I could not google it. Not sure...

It could be some form of a single-jack stereo-input, maybe a coaxial input for an internal DAC?

I have received a new amp about a week ago - latest Eufonika model named H5DS (H5 Dual-Selectable). It's a customised/new version of the well-known H5 with the following distinctive features: 1) Driver tube: 6V/12V heater voltage selection. 2) Driver tube: automatic bias/support of different...

It would be interesting to know, if there are any affordable options in that area worth considering like Little Imp Tube Tester or Orange Valve Tester, or maybe this unfortunately *named newcomer: https://www.ebay.co.uk/itm/234188446152...

A different one on eBay: https://www.ebay.co.uk/itm/313689639119 Interesting that it comes with an early square-getter 6n5s and an early-ish Foton 6n8s - both more rare than typical 80s 6n13s and Reflector/Nevz 6n8s.

@Paladin79 what is your opinion on Soviet paper-in-oil caps?

Thank you for the explanation - I have a lot to learn! No, I am only starting with some audio effects for now - one step at a time. The adjustable bias amp is one of Garage1217 ones (schematic is here http://www.mediafire.com/file/06g72zyu2d32gp6/Sunrise_3.1_schematic.pdf/file).

@L0rdGwyn are designs you are using all self-biasing? I was recently thinking of using a VU-meter for visualising transistor bias in a guitar pedal. It kind of works on a breadboard with a resistor in series, but I have concerns about precision and the idea in general. I also have a headphone...

Simply multiply the price by an arbitrary integer: https://wooaudio.com/tubes/tungsol-5998

Tell me about it... "Handling fee"? I did not ask you to handle my stuff to begin with!

They were fine. Though that tells nothing about any other batches - especially the used ones. I did wonder whether customs would check everything incoming for radioactivity just in case? Probably not.

Yes.

Verification by hammer? I bet glass is the weak spot in that tube...