Winter DIY OTTAWA MEET

[mwmkravchenko]

Yep there is always something cooking in the kitchen!

[Kevin_Murray]

Thanks guys, I've actually got a few projects on the go. In various states of incompletion of course. I have a 3 way TL tower that I started a few years ago. I'm close to abandoning it because of the size of the enclosure. It looks like it will become a simple vented tower in a tear drop profile. I also just finished restoring/modifying an old pair of Pioneer CL-100's. It was just a fun project to see what I could do on a beer budget.

As far as electronics go I have a few amps I'm working on. One is a Holton design I built years ago and never put into a chassis. It's an all N-channel output type which performed like crap. It needed several modifications just to make it stable. The ouput oscilated at ~2MHz and destroyed several sets of output devices. Eventually I bought a scope and found what was causing it. Adding a pole to the VAS solved it. The amp still has thermal issues with the bias cct. and he (Anthony Holton) eventually gave up and withdrew the design from his website. Someday I'll use it for a subwoofer amp I guess. It uses 3 pairs of IRFP240 devices and runs on +/-75 volt rails. Could destroy any speaker I own without breaking a sweat.

Another is a 4 channel gainclone for bi-amping the CL-100's. I had an old NAD 2140 which I gutted and will stuff the gianclones into. Too bad I didn't see Tyler's website before I bought the pcbs. I paid the same price out of country.

The last is a high performance hi-fi amp that I designed from scratch. The only thing holding me back is lack of a pcb. I just can't bring myself to spend the dough when I have so many other expensive non-audio projects.

Other than that I have a few toys I could share. A few miniDSP boards with 2way and 4way firmware, measurement software and a few decent 'scopes. Oh and a Behringer CX2310 in case anyone wants to try bi- or tri-amping their speakers.

One thing I would like to do is calibrate my mics against someone else's calibrated unit. They're just an RS SPL meter and a cheapo Naiant recording mic. The Naiant is supposed to be omni and fairly flat.

[mwmkravchenko]

As for mics it's not the tools you own but how you use them. If you have a reference curve it is still a pretty powerful tool.

And your electronics look very interesting.

Should be fun for the next one.

[Kevin_Murray]

Originally Posted by mwmkravchenko

As for mics it's not the tools you own but how you use them. If you have a reference curve it is still a pretty powerful tool.

And your electronics look very interesting.

Should be fun for the next one.

True, and I have the standard correction for the RS meter. I was mostly curious how they perform. I'm also toying with the idea of linearizing the A-weighted setting of the meter so it's Z-weighted. I would still have the question of the mic response though. Anyway look forward to the next meet.

[ripcard]

So I'm going to have to be more proactive when packing up from these events in the future. I discovered last evening that I'm missing a disc. Dire Straits-Brothers in Arms SACD. Case is empty. The last time I played it was at the event. Went through the cases that I brought and it's not there, nor is it in the player I used. Odd that there would be a bare disc missing but there it is. Can anyone who brought discs please check their cases and if the player you brought hasn't been used since, can you check the tray for this disc. Thanks, Rick.

[mwmkravchenko]

I'm not guilty!

Did you get your Philips screwdriver?

[ripcard]

Thanks, Mark. The screw driver was found. I just won't have it until the next get together. Same with the power bar I left behind.

[mwmkravchenko]

We were all tired Rick. At least the stuff is in good hands.

[ripcard]

Yeah, no worries about the driver and the PWR bar but the disc is a bit of a concern. Seems odd that I would have an empty case.

[mwmkravchenko]

Ok gents here is the beginning for the next one:


DIY OTTAWA WINTER 2012