I am looking to connect with any DIYaudio folks anywhere near Traverse City, Michigan.
I am a few years out from retirement but I can see it from here. I am hoping to find new homes for a whole series of amps or even just to part them out so that the dumpster is not fed. I'm looking for advice. It would be great to meet a fellow enthusiast on the local side too! There seems to be no DIY audio postings from the area or even in Michigan. I'm feeling like a Dodo, soon to be extinct 😳
I am a few years out from retirement but I can see it from here. I am hoping to find new homes for a whole series of amps or even just to part them out so that the dumpster is not fed. I'm looking for advice. It would be great to meet a fellow enthusiast on the local side too! There seems to be no DIY audio postings from the area or even in Michigan. I'm feeling like a Dodo, soon to be extinct 😳
Attachments
Would love it if you could talk through that amp in the picture. Looks like the culmination of a lot of hard work.
Thank you for the links! I understand that Covid knocked the stuffing out of all meetings, I can only hope something comes to life again. These things are much like a band... they have a life span...
Sure! That amp is an all out effort on a first build, a build to end all builds I thought. Ha! I have built so many amps in the last dozen years! Anyway, the pictured amp was my first. It is a straight ahead attempt at a 45, driven by a (paralleled )12BH7A. The enormous size is a result of trying for the lowest possible DCR. There was only one resistor (1k on the grid wire to prevent possible oscillation) in the whole amp. PSU is CLCLCLC(CL) for each channel using big old Hammond 193 series L's. Twin power transformers to halve the resistance and a bridge rectifier of 6D22S TV damper diodes. Twin mono blocks. Fixed bias with grid and plate chokes, cap coupled with all final "C" filters of the best poly sort. It was sweet! It was dynamic too! I built that back in the 2010s. I hardly knew what I was doing at all! I ended up doing many experiments on it trying to make things better - sometimes I did!
The coupling cap and output transformers were the places I found where well worth investing in. I learned quite a bit by experiment. I bought my amp jewelry like vintage Weston meters and gold plated copper binding posts, they did nothing to make the amp sound better. Changing out capacitors (except the CC) has little effect. The tubes DO matter but mostly one has to take the whole circuit as it is. I am not sure I brought that design to perfect form but I did my best.
Better parts make amps better but the circuit it the thing, synergy in design not so much the name/category of the design it is a matter of testing the entire design... by building it and listening. Lots of experiments, lots of listening, and lots of money. If you ever hear a design you love, build that amp. All the hear ache has been gone through for you already. Thank that designer profusely.
As much as I loved that amp, I rebuilt it several times, I have since found that, for my ear and speakers, I have built better circuits. That amp is torn down now.
I have done similar exploration in SS designs with different speakers and my mainstay: my La Scala. I have explores PSU design and found that as extreme as the one in the picture is... I can do better now, not lower DCR but better none-the-less. Besides, I can't lift as much weight as I once did. The pictured amp weighed some 80 pounds each. Now I build a separate PSU and separate chassis for the two channels. No more mighty, mighty rail structure though I would not disuade anyone from doing that on a first build... it is amazing to work and think in a linear fashion ;-)). Good thing I chose aluminum and not steel!
So many factors go into building not just a good amp, there are many good amps to build, but building one that makes your heart sing. That first one did make my heart sing but as with all love, one needs to go deeper and deeper and then realize that to everything there are limits and compromises. We must all find the comfortable that still allows the occasional swoon. That's why I am still building...
Two more pictures, one of the old and one of the new...
Cheers!
Attachments
They are epic! Thanks for the insight.
What was the verdict on coupling capacitors? Do you have a favourite?
What was the verdict on coupling capacitors? Do you have a favourite?
Good packaging on the new.
The AES student branch is probably still going, and should welcome guests.
Michigan Tech is about 370 miles from Traverse City, surprisingly.
I live in Traverse City, at least part of the year. Not many tubes here, though.
I live in Traverse City, at least part of the year. Not many tubes here, though.
It’s a matter of getting what you pay for, by the time you get to the best you might as well get an interstage transformer. The only bargain out there are the Russian Teflon military surplus.
I was wondering about stirring something up with SMAC , some kind of large swap meet. Car guys have it easy, ride to a special burger joint and pop your hood! We all need rooms and power, time to set up, tear down, like fifty tiny concert halls 🙃