The 12AY7 is fine and it's hard to say whether you were offered inferior value with a Chinese 12AX7; I have been very happy with some Chinese bottles and very unimpressed with others and I'm no exception in this respect.

Here's a datasheet for the 6P6P but you'd have to figure out how close it really is to the 6V6GT because it is all Chinese.

The 5AR4 is a GZ34 substitute and definitely 'better' specs than the 5Y3 - only really better if you are looking for headroom since the 5Y3 sags more. Your amp will be 'browner' ie more 'spongy' if you put the actual 5Y3 in and the 5AR4 will make the amp more direct, sortof midway between solid state rectification and the original 5Y3.
Shuguang is the best known Chinese factory, producing some really good stuff. Their global market share is supposedly 40% of all new tubes but I have no way of verifying this. Many amp manufacturers rebrand Shuguang bottles to read their 'own' brand name.

AFAIK, the 6P6P is supposed to be a Chinese 6V6. I've never used them though.

I have some Shuguang tubes which get the job done quite ok... I guess there are brands with more Mojo, but dont fret.

If they can be used without modification of the circuit (which may well be the case) then use them for now. You can buy 'better' valves later. I got some modern 5Y3 rectifier valve with my Tweed kit and I'm using a JAN NOS 5Y3 now and I bought some Tung-Sol 6V6s to use instead of the JJs I got (one rattles). I would highly recommend using that 12AY7, the Tweed has basically no clean headroom and using a 12AX7 in the preamp will turn it into an overdrive-only amp }?

Congrats. Post pics as you build!

How do you guys rate these kit amps? I've seen some on ebay etc... Considering getting one sometime.

warrenpridgeon wrote: How do you guys rate these kit amps? I've seen some on ebay etc... Considering getting one sometime.

It depends. Not all amp kits are made equal. Some are of the same or better quality (Trinity, GDS) than The Real Thing(TM) and some are cheap (Mojotone) ways to get something like that amp you've always wanted. Beware the cheap ones. They may not have been designed carefully to result in a clean, reliable build with high quality parts. Kits like those you get from Trinity have been carefully put together from top quality parts and the layouts have been designed to minimise noise and other issues. Do not be fooled by price alone. Amp kits are heavy (even a Tweed kit without a cab and speaker is hefty) and shipping cost is significant ~ add $200 or so to any kit price you see if it comes from the States or Canada.

Usually the kits are for vintage style amps because those were simple and relatively easy to build without too much hassle. More modern amps (late 70s and newer LOL) have significantly more gain than those older designs and as such requires a lot of care to build successfully without having issues with noise and oscillations (squuuuuueeeeeeeeee!!!!!!).

That all said, playing an amp you have built yourself is awesome.

Do remember that valve amps contain high voltage DC and can kill you if even when they're switched off.

Also check out http://www.mrvalve.co.za/wmenu.php. They are most helpful in testing valves and letting you know at least if the specs are good and what alternatives there are for you. If the values of the Chinese valves are way different than that of the trusted standards like Sovtek, Tungsol, JJ, Electro Harmonix or the like rather go with the trusted ones. Mr. Valve's prices are waaay better than getting valves from most retailers too.

I've got Ruby's and a couple of different Chinese ones which were just flat in their respective amps I got them in. On replacing them with Tungsol (5881's - same as 6L6's) and Electro Harmonix (ECC83's / 12AX7's) bought from Mr. Valve the amps in question livened up tremendously. Even a very well-used Electro Harmonix 6L6EH sounded better than the Chinese 6L6 (once I found one of the four I had which wasn't popping and crackling from years of use / misuse).

Also the Tungsols are notoriously tough and long lasting, especially if you gig regularly but still do the power on / off sequences correctly and patiently. They even sound better to me than the Groove Tubes I had in my Peavey 6505.

Just make sure you have the necessary knowledge on biasing for your project. I'd assume there would be some sort of instruction in the kit but, if not, take it to a valve technician to adjust to have the valves running just right (not too hot or cold).

Leon_AiA wrote: Just make sure you have the necessary knowledge on biasing for your project. I'd assume there would be some sort of instruction in the kit but, if not, take it to a valve technician to adjust to have the valves running just right (not too hot or cold).

5E3 is cathode biased. Plug and play!