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View Full Version : Has anyone bought one of these preamp kits from ebay?



Primalsea
13-01-2018, 15:52
https://www.ebay.co.uk/itm/Douk-Audio-Hi-Fi-6J4-6P6P-Valve-Tube-Preamp-Class-A-Pre-Amplifier-Kit-for-DIY-UK/272296137754?_trkparms=aid%3D111001%26algo%3DREC.S EED%26ao%3D1%26asc%3D20160908105057%26meid%3D4a230 73e94e444ed92d6deb3990b7f93%26pid%3D100675%26rk%3D 2%26rkt%3D15%26mehot%3Dpp%26sd%3D272135607554&_trksid=p2481888.c100675.m4236&_trkparms=pageci%253Abd37212f-f878-11e7-85b1-74dbd180ae05%257Cparentrq%253Af03238151600aa11f615 0bc0ffdf199e%257Ciid%253A1

Has only bought one of these?

I dont want to make this particular kit. I have an idea of a design and want to try out different valves. I’m thinking that I could build this but with a few modifications, so I can easily change out the plate and cathode resistors in order to try different tubes. For the different pinouts of the tubes I would have to make adapters, but this shouldn’t be too much of an issue.

Firebottle
13-01-2018, 18:24
Yes and why not Paul? I haven't actually bought one of these myself.
If you can put together a power supply and aren't particularly interested in the case then you could go about it for a lot less. There are pcbs available for different preamps.

One word of caution with a kit like this, I have modified a Douk preamp, on 240V mains the voltages were a bit high, not such an issue for the HT but over spec for the heaters> I fitted a bucking transformer to lower the mains fed to the mains transformer.

:)

Primalsea
13-01-2018, 19:15
Good point about the voltages. I had forgot that the Chinese mains is 220V and the stuff they churn out tends to be designed for this. It will run at our Higher 230 to 240 volts (242 where I live), but as you say the heater voltages tend to be a touch above what we would really like.