Wooden amps…

Well, not completely wooden of course! Some years ago I showed a plan to make a set of amps with wooden front panels, because I picked up some pre-cut wood in the right dimension on one of my trips to Japan. A while back the plan was resurrected, but then immediately brought to a halt because I had to enlarge some already-drilled holes and managed to destroy one of the panels in the process – bummer!

However, in the mean time I’ve found a local place that sells wood trim pieces for professional craftsmen and in their assortment I found a pre-made profile in the right dimension for a 1U panel and in several different kinds of wood. I chose oak as it is more my thing than the darker wood types and it goes well with both black and silver fittings. I’ve recently invested in a better drill press, so redoing the panels were without accidents this time and I also managed to overcome my fear (or is it loathing) of doing cabling to finally complete the set 🙂

The set consists of a DCB-1 preamp (on a clone board), meaning a DC-coupled version of the classic B1 buffer circuit, and a Hifimediy T4 Tripath-style class D power amp. The power supply is a surplus N2 XL375-type which I bought a small stash of some years ago.

No detailed listening impressions from my main system yet, but on test speakers it sounds excellent as I expected from what is basically an “evolution” of my old B1/125ASX bedroom system. Both components include relays to minimise turn-on and turn-off thumps and so as a set they are well-behaved enough for daily use (which is always one of my success criteria). As far as the looks are concerned, I could honestly see this being something I will want to try again in the future…

Tripath TK2050 monos…

Well, it’s been a while since I posted a project that was actually finished…. and this one isn’t either 😀

It’s a pair of monoblock amplifiers based on Arjen Helder’s Tripath TK2050-boards. Arjen Helder is/was a Dutch guy living in China who around 5 years ago sold some great DIY boards based on the Tripath class D ICs. He’s probably mostly known in the DIY-community for the low-power TA2020-based amps, but he did make a few designs based on the more powerful TK2050 chipset as well. I bought a couple of the TA2020 boards when they were available because they were cheap and sounded great, but I managed to stay away from the TK2050 boards back then because I did not have anything to use them for (come to think of it, I don’t now either… 🙂 ).

Unfortunately I am nearly powerless to resist the temptation of an ebay-bargain so I snapped up this pair that I stumbled upon a couple of months ago without much hesitation. Originally, the plan was to mod the boards a bit replacing the stock capacitors, in/out connections etc. However, some of the traces seem to be very thin and as it isn’t possible to get a replacement board if I damage something I limited myself to just replacing the input caps.

The power supplies are a couple of Mean Well EPP-150s which were “left over” from my JLH-Evo build. They should be more or less spot-on for this when used in dual-mono mode and the small 4” x 2” size is an advantage as well.

The mechanics consist of pair of Chinese-made enclosures (selected because they were the right size for the job…) with custom rear-panels. I was going to use the stock rear panels, but a couple of stupid measurement-errors that I did not notice until after drilling made that a lost cause 😉

What’s missing is only really a few cables, but that isn’t my favourite part of a build and so I might save it for a long dark winter’s night instead 😉

Past projects: 6-channel Tripath amp

Well, without time to finish new projects, it’s time to (once again) go digging in the “back catalogue” instead 😀

Here is my first DIY multichannel amplifier. This is based on three Tripath boards from Sure Electronics that were “flavour of the month” some years ago. The boards are based on the TK2050 chipset with the output drivers in bridge mode (so up to around 100W output per channel according to the specs). The boards are stock except that I removed the clamping diodes on the input (which protects the ICs from excessive input voltages) and replaced the (small and horrible) ceramic input caps with (slightly better) Nichicon Muse ES bipolar electrolytics. The boards shown here are the first version that was passively cooled, all future versions I have seen are cooled by small fans. The heat sinks get fairly hot (around 50-55C) when the boards are running.

The PSU is a Mean Well USP-225-24. This is a little under-powered for five/six channels if driven at high levels, but I have a small room and even driving the relatively difficult 4 ohm Elac speakers I never had any issues with clipping. I actually have a spare USP-350 PSU that I have planned to put in instead for a bit more headroom. However, since I don’t use the amp at the moment, for now that is just one more point on a very long to-do list 😀

I was originally not going to show this until after it’s been rebuilt with the more powerful PSU, but as I am not getting to that anytime soon here are some pictures anyway 🙂

Past projects: Tripath TA3020 amplifier

What do you do with a leftover transformer? Well, you buy a matching amplifier board for it, don’t you? Yes, even when I built this a couple of years ago I needed an extra amplifier about as much as a goldfish needs a new bicycle, but still – it’s fun!

The base of this is a custom-wound toroidal transformer from toroidy.pl that was left over from another project and a cheap and cheerful amplifier board from ebay. The amplifier board is based on the Tripath TA3020 controller chip and some “high-tech” IRF MOS-FETs. The board has everything onboard and all that was needed was a bit of wiring and some token heatsinks 😀 The casework should be instantly recognisable to readers of this blog as well, nothing fancy about that at all – Modushop and Schaeffer all the way. The only “blemish” is the RCA sockets which are silver plated – in theory a brilliant thing for both sound and looks, in practice quite stupid because they tarnish badly the moment you turn your back!

This amplifier sounds surprisingly good. It deiivers a much bigger soundstage and much better detail than I was honestly expecting (although I had heard good things about the TA3020 beforehand). The original plan for the amp was to build it, test it and then sell it on if it didn’t work out, but it actually (to my surprise) turned into a definite “keeper”. It has also “survived” the subsequent arrival of both the ICEpower125ASX and the Pass F5 projects, although these both have qualities that the Tripath-based amp can’t match. However, for “good sound on a budget” this is doing a very good job indeed.