Cheap Tube Amp Kits?

I have seen many cheap tube amp kits for sale on Aliexpress and eBay. I realise that these kits will probably have lower quality components and likely not perform to advertised specs. My question is are these worthwhile purchasing to gain building experience before attempting one of the projects on this website or are they just a waste of money?

7 answers0 replies

7 Comments

Just Me

Feb 11, 2023

I would say yes, build one. There is one that I am building right now. On YouTube, xraytonyb has done a thorough job of building and testing it, and it does perform to spec. The components are reasonably high quality, except maybe the volume pot and one power supply cap that I will replace. It comes with a 115V transformer now. I am hoping that will be close enough to work ok. My wall outlet is exactly 120V.

You can see the building and testing by xraytonyb in detail here:

Part 1: https://www.youtube.com/watch?v=lkImhOoAnSA

Part 2: https://www.youtube.com/watch?v=fD83Oi6gCUs

Part 3: https://www.youtube.com/watch?v=0nDsGJn_BEM

Note that the amplifier kit has been updated to remove the loudness circuitry, which was the first modification that xraytonyb made. The loudness switch and the associated circuitry are gone now thankfully. The rest remains unchanged.

If you order from AliExpress, you will see large differences in the price for the same amplifier kit. I chose the lowest price seller, and we have been having a little communication difficulty. Make sure you are comfortable communicating with the seller BEFORE you buy, in case it arrives with missing parts or damage. Try chatting with the seller using the messenger tool before buying. You can also find the amp kit on ebay, but at higher prices.

https://www.aliexpress.us/item/3256804139705130.html

The new building instructions and Q&A can be found in this discussion thread:

https://www.diyaudio.com/community/threads/6p14-el84-amplifier-kit-building-questions-before-i-build-maybe-during-if-i-do.394962/

Mine took just 6 days to ship from Hong Kong to Florida. Here it is:

Also on YouTube, xraytonyb built another one of the inexpensive amp kits that also turned out quite well for him. He did a 10-part video series on it called "Electronics 101-1/2."

https://www.youtube.com/watch?v=YqD_4tkRcts

mddawson

Feb 11, 2023

Replying to

Here is the Korean playlist (no speaking but all the on screen captions are in Korean): https://www.youtube.com/watch?v=nUK4sOOE7WQ&list=PLnyQFHUSljIpCy0KD6aTbms7K0Mb5Krhx Here is part 1 (of 6) of the Thai series. This guy does a better job IMO as he insulates the longer resistor leads and seems to take more care with wire placement: https://www.youtube.com/watch?v=kSG8v8h-E-M Both YouTubers have the main power transformer spaced from the top of the case leaving a gap. I am assuming that removing the four nuts on the transformer could affect the plates so I am thinking of drilling larger holes and using spacers around the nuts to secure it to the case.