Search found 491 matches

by Thermionic Idler
Wed Jan 01, 2020 10:30 am
Forum: Computer Audio
Topic: Daphile
Replies: 2
Views: 268

Re: Daphile

Works with spare Macs too, our setup currently uses an old 2008 MacBook although the plan is to incorporate a NUC with a linear power supply later on. Mostly controlled using Squeezepad, it works faultlessly, and most importantly it supports gapless playback which has been a frustration with every o...
by Thermionic Idler
Sat Dec 21, 2019 4:40 pm
Forum: Assorted Stuff
Topic: Squeeze box down!
Replies: 32
Views: 1112

Re: Squeeze box down!

vinylnvalves wrote:
Sat Dec 21, 2019 1:08 pm
I changed over to Dalphile a year or so back.
Same here, Daphile really has a lot to recommend it. We've done away with the physical CD player now and just have the server.
by Thermionic Idler
Mon Dec 16, 2019 11:02 pm
Forum: Assorted Stuff
Topic: Mains filter - made things worse?
Replies: 13
Views: 733

Mains filter - made things worse?

So here's a rather interesting thing that I thought I would share. I have a Kemp Elektroniks power strip which I've owned for about 10 years or so (this one: http://www.kempelektroniks.nl/en/222/kemp-elektroniks/products/shunt-conditioners/power-strip ) which incorporates (allegedly) a noise filter,...
by Thermionic Idler
Tue Nov 12, 2019 4:44 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

What is the bandwidth of the oscilloscope? My point entirely... It's a second-hand Tektronix 466 which apparently goes up to 100 MHz, or at least it did when it was new. I might need to get better probe connectors for it though, the one it came with disintegrated a few years ago and I bought rather...
by Thermionic Idler
Tue Nov 12, 2019 2:48 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

I'd just bung it across on the track side. :D Sadly it's a double sided PCB with insulated tracks... :( I think Mike means the side without components. You can scrape the resist of the tracks if there isn't a convenient soldered point. is there any frequency compensation in the feedback loop? Good ...
by Thermionic Idler
Tue Nov 12, 2019 2:32 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Mike H wrote:
Mon Nov 11, 2019 2:03 pm
Thermionic Idler wrote:
Mon Nov 11, 2019 12:39 pm
Thanks Mike - might be worth a try. This bit is on the PCB so adding it could be a touch fiddly.
I'd just bung it across on the track side. :D
Sadly it's a double sided PCB with insulated tracks... :(
by Thermionic Idler
Mon Nov 11, 2019 12:39 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Now, when I put the voltmeter probe on V1A pin 6 (the anode of the first stage) the oscillation stopped dead, and I got a 105V measurement against a spec of 100V. Could that have any significance? Which I think added a bit of capacitance to the anode, and loaded it in the HF / ultrasonic region, th...
by Thermionic Idler
Sun Nov 10, 2019 6:43 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Thanks everyone. We’re breaking them in with the Lord Of The Rings trilogy :D
by Thermionic Idler
Sun Nov 10, 2019 6:23 am
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Happy days! So later on last night, I connected up both amps to the preamp, but connected the load resistors instead of the speakers. The bias was set, and stayed absolutely rock steady. I then put the oscilloscope on both channels to monitor them for over half an hour to ensure nothing untoward hap...
by Thermionic Idler
Sat Nov 09, 2019 5:52 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Not yet, but I think I have identified the culprit. The question is - what is the solution? Shorting pins 2 and 3 of the XLR input, i.e. the primary side of the line input transformer, stopped the oscillation dead in its tracks. This was consistent and repeatable. As I said previously, there is a le...
by Thermionic Idler
Sat Nov 09, 2019 4:56 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

OK here are some more data points. All the resistors in the global feedback network seem to check out okay. I saw nothing that looked visibly burned out when examining inside. All the voltages that I was able to measure (i.e. where the circuit wasn't bouncing up and down in oscillation) were within ...
by Thermionic Idler
Fri Nov 08, 2019 7:34 pm
Forum: Assorted Stuff
Topic: Floods
Replies: 10
Views: 671

Re: Floods

Glad you guys are okay, of course we lived in Chesterfield for five years up until just under a year ago so I recognise all the areas that are currently being talked about on the news.
by Thermionic Idler
Fri Nov 08, 2019 9:36 am
Forum: Everyones Projects
Topic: WAD 300b completely kaput - advice please
Replies: 7
Views: 518

Re: WAD 300b completely kaput - advice please

adrian wrote:
Thu Nov 07, 2019 10:09 pm
Greg is spot-on. John has responded on the other forum and I plan to drive over at some stage
Thans
Adrian
Ohh nice! Definitely repair it if you can, I remember it being a lovely sounding bit of kit.
by Thermionic Idler
Thu Nov 07, 2019 7:00 pm
Forum: Everyones Projects
Topic: WAD 300b completely kaput - advice please
Replies: 7
Views: 518

Re: WAD 300b completely kaput - advice please

Hi Adrian

Is this the 300B push-pull or something else?
by Thermionic Idler
Thu Nov 07, 2019 5:27 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 300
Views: 49467

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

I would have thought not. It's likely the higher gm valves ecc83 don't tend to sing. Did you measure the frequency of the oscillation? Not yet, I need to get it back on the bench and do some proper measurements. This was just a very quick diagnosis to find out why my load resistor had got so hot, u...