I've heard it - it's very good.
This is a hard question for me.
DIY amp and speakers and source - wow! The best systems I've ever heard were a mix of commercial product, DIY and MIY (Modify It Yourself).The best all around* DIY amp I've heard would be Jean Hiraga's 300B.
Best from scratch DIY speaker might be John Bush's P.Audio 18" coax on open baffle.
* Best used fullrange on medium to high sensitivity speakers. Other amps are better at certain sections of the spectrum, but not overall.
This one is SE, but sound is very clean and transparent. Absolutely no global feedback. 5W per channel.
www.wavebourn.com • View topic - Gubernator-7: 4P1L Single Ended Amplifier Design
This one is PP with several feedback loops, but as well is very clean and transparent. 80WPC limited by optical compressors (100+ before clipping).
www.wavebourn.com • View topic - Pyramid-VII: home stereo vacuum tube amp
www.wavebourn.com • View topic - Gubernator-7: 4P1L Single Ended Amplifier Design
This one is PP with several feedback loops, but as well is very clean and transparent. 80WPC limited by optical compressors (100+ before clipping).
www.wavebourn.com • View topic - Pyramid-VII: home stereo vacuum tube amp
I'm in this ppp BIG GAME....Agree on weight but less chance of getting stolen....I question THD with OTL tube power designs......certainly shows up the flaws.
Optical compressors: I'd worked on this way back in the 1980's for outside PA but it needs a good one series parallel combination to avoid thd.
BTW; that poll is in the wrong place...hence so few respondants... and not concealed within a thread. It should be on the front page.
richy
Optical compressors: I'd worked on this way back in the 1980's for outside PA but it needs a good one series parallel combination to avoid thd.
BTW; that poll is in the wrong place...hence so few respondants... and not concealed within a thread. It should be on the front page.
richy
I use them to avoid clipping. They sense screen grid currents and start working sharply above 80W per channel.
Speaking of PPP, I have a project on staples, 4xGU-50 per channel, for 200WPC.
That's more like the hog.... I presume bandwidth...down to 15Hz.....to blow rubbishy SE away..... ?
richy
Attachments
Augmented source followers loaded on counter-modulated current sources do that easily (and even better!), but not in summer.
There are many good things out there, at some point, there's only "different", not "better". I personally like my self made Duetta speakers, designed by Audio Design Wohlgemuth very much and wouldnt exchange them for anything. And I've never heard them play as nicely as when I tested my KT88 Hafler Style Amp with them. I'm realy looking forward to the day, when they are finaly ready, I havent had any time to work on them for over a year. That'll be just gorgeous...
Since I make my own amps, I have a slightly biased opinion towards them. I have built at least one of every topology in the poll except for the OTL. I built an OTL, but I wound up sticking a transformer in it and taking feedback out of it because it sounded better that way.
I have several amps around and I listen to one or two for a while then swap to another when I grow tired of what I am listening to. I have two favorites that I keep comming back to. They are from opposite ends of the power spectrum:
I have the very first Tubelab SE it uses 45's or NX-483's to make 2 WPC through 10 watt Electra-Print OPT's. I listen to it a lot even through my Yamaha 87 db speakers. It has seen a lot more action lately since I have made 2 sets of high efficiency horns. I have taken the TSE to several listening sessions for comparison with some high dollar stuff. On one occasion we put the TSE next to a pair of Cary 805's. We were using 106 db Lowther based horns and the TSE just sounded better. The results would have been different on lower efficiency speakers.
The other amp that gets a lot of use isn't one of mine, although it has been "tweaked" by me just a bit. Pete Millet designed a P-P amp using sweep tubes for a conservative 18 WPC. I made a few changes to get up to 250 WPC. Several of us decided on a rather easy to make 125 WPC build which has been documented in the thread. It is clean and detailed enough to play at low power levels on the big horns, but can do "rock concert in the living room" when cranked up into the 15 inch Silver Iris OB's.
http://www.diyaudio.com/forums/tube...-new-p-p-power-amp-design.html?highlight=6gv5
I have built a PPP Simple P-P using 8 X EL84's for 50+ WPC. Sounds good, and a bigger PPP is on the list because I have a set of 400 watt OPT's but I don't really need an 800 watt amp so it isn't a high priority.
I don't remember the name Sandcastle, but Chris is referring to the amp we co-designed in this thread. I still have mine but it has never been put into a proper chassis. Part of the reason is the flexibility in the driver board. It can be used in amps from 10 WPC to the 400 WPC PPP amp discussed above. I was leaning toward a 10 WPC version. Still there were two. One was a 45 in AB2 and the other was a fully differential (including the output stage) class A triode amp using KT88's.
http://www.diyaudio.com/forums/tubes-valves/133034-6l6gc-ab2-amp.html?highlight=6L6GC+AB2
It is so cool
and inspirational to read these replies
I'm in the nascent phase of the test and measurement universe. Researching instruments, assembling a lab/bench, learning proper technique...
All very gratifying
I hope to implement some of the designs/circuits featured on this site and perhaps, even create something interesting before it's all said and done
and inspirational to read these replies
I'm in the nascent phase of the test and measurement universe. Researching instruments, assembling a lab/bench, learning proper technique...
All very gratifying
I hope to implement some of the designs/circuits featured on this site and perhaps, even create something interesting before it's all said and done
<<<PP
Sorry, I did not elaborate on the 'Tubelab Sandcastle amp'. As the topology bears a resemblance to Morgan Jones 'Crystal Palace' amp using solid state in places where Morgan Jones uses tubes, it sounded like a good name. I think Tubelab is being rather generous when he says we 'co-designed' the amp. Tubelab was extremely patient helping me adapt his design to the specific tubes and transformers I had. After a little teething trouble setting them up (due to my building techniques and some early parts failures, not due to design) I have about a year's worth of trouble free daily driver listening on them. They look and sound great.
Thanks Tubelab!
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