L0rdGwyn's DIY Audio
May 4, 2021 at 10:09 AM Post #2,507 of 2,708

Tjj226 Angel

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Well actually I misspoke, the mechanism of thermal runaway is a bit different, but ultimately the death of the tube is reached by similar means, the grid becomes more and more positive, the tube conducts more current, and the internals melt.

Yeup. Just for clarification for everyone else, thermal runaway occurs when heat causes a part to become more conductive. The higher conductivity means the part will draw more current, which will create more heat, which will raise the conductivity, which will lead to more heat etc etc.

It is a cascade effect that is caused by the heat itself. This is more common with BJTs which is why companies like schiit usually have some type of circuit monitoring the heat in the amp.
 
May 7, 2021 at 5:27 PM Post #2,508 of 2,708

L0rdGwyn

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I know I'm in danger of being sucked back in with how much I have been posting on this thread lately, but I am on night shift, I need every bit of dopamine I can squeeze out of the old brain.

I made some furniture changes, my two-channel system is nearing the end of my roadmap for it, all that is left is to put the 801A amp in rotation with the 6A5G SET. There truly isn't any more room in my house for more gear, so not sure what happens when it's done, besides small tweaks to existing builds. Maybe I'll add an addition to the house :)

PXL_20210507_205647686-4.jpg
 
May 7, 2021 at 5:47 PM Post #2,510 of 2,708

bcowen

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I know I'm in danger of being sucked back in with how much I have been posting on this thread lately, but I am on night shift, I need every bit of dopamine I can squeeze out of the old brain.

I made some furniture changes, my two-channel system is nearing the end of my roadmap for it, all that is left is to put the 801A amp in rotation with the 6A5G SET. There truly isn't any more room in my house for more gear, so not sure what happens when it's done, besides small tweaks to existing builds. Maybe I'll add an addition to the house :)

PXL_20210507_205647686-4.jpg

Sweet! Tubes, vinyl, and Snells. Sometimes you just have to know when to stop. LOL!

(and if you ever figure out when that is, please share :smile:)
 
May 7, 2021 at 6:06 PM Post #2,511 of 2,708

whirlwind

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I know I'm in danger of being sucked back in with how much I have been posting on this thread lately, but I am on night shift, I need every bit of dopamine I can squeeze out of the old brain.

I made some furniture changes, my two-channel system is nearing the end of my roadmap for it, all that is left is to put the 801A amp in rotation with the 6A5G SET. There truly isn't any more room in my house for more gear, so not sure what happens when it's done, besides small tweaks to existing builds. Maybe I'll add an addition to the house :)

PXL_20210507_205647686-4.jpg
Very nice.
 
May 7, 2021 at 7:21 PM Post #2,512 of 2,708

L0rdGwyn

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@L0rdGwyn in terms of sound on average are rectifiers worth bothering with or hexfred/schottky is the answer?

It's a bit controversial. From a purely technical / design standpoint, solid-state rectification is better, there really is no advantage to using tube rectification that cannot be duplicated / improved upon with solid-state components. Two positives going for tube rectifiers are their "soft-start" characteristics and inherent snubbing of transformer ringing due to their high internal resistance. But, again, these two issues can be easily addressed using solid-state rectification.

One particular use case for tube rectifiers - if you are attempting to adapt a mains transformer you have on hand to a specific design and have some excess voltage that needs to be dropped in the power supply. In that case, getting the heat outside of the chassis by dropping some voltage across a tube rectifier might be preferable to dropping it across resistors in the power supply, which will generate heat inside the chassis.

From a sound perspective, you sort of have to buy into what I will call "tube rectifier voodoo" to decide if you think it is worth doing or not. Other than altering the bias point of the amplifying tubes using different tube rectifiers with varying Vdrop (which surely contributes to the notion that tube rectifiers can change sound), if you want to "hear" a tube rectifier, you better use a passive power supply, as opposed to voltage-regulated. The power supply rejection of a high-performing voltage regulator will be so high that anything before the regulator in the supply will be essentially inaudible, including the rectifier. Also, the regulator will nullify any changes in bias point due to different Vdrop of the rectifier. So if you want to "hear" the rectifier, have to go passive (this means only RC or LC filters in the supply, resistors, capacitors, chokes).

My 6A5G amplifier has a passive power supply that is tube rectified. I played around a bit with trying different 4V rectifiers, differences heard between them I would say were small to the point of uncertainty, but I did give the slight edge to the U18/20, plus it looks cool - this is the real benefit of tube rectifiers :wink:

I have used solid-state rectifiers in all subsequent designs. Here is my personal opinion - tube rectifiers look cool and give the amplifier swag, but I will not use them unless I need to drop some excess voltage using an off-the-shelf or on hand mains transformer in a design, or if I just want the amp to look a little cooler. There are so many other aspects of an amplifier than will affect the sound more so than a tube rectifier, so my preference is to go solid-state and seek out those changes instead.

Just my opinion, opinions will vary by who is designing the amplifier and their personal experiences.

Sweet! Tubes, vinyl, and Snells. Sometimes you just have to know when to stop. LOL!

(and if you ever figure out when that is, please share :smile:)

I THINK I am going to pump the brakes hard when this system is done. The sound I am getting is goosebump generating, that's the benchmark for me, so I'm good :D I'll probably make or buy some cool interconnects and stuff like that, I have a laundry list of tweaks that need to be made to the gear I've finished, so that's probably what I'll work on first. Then there is this SIT power amplifier, the HK54 A2 amplifier, upgrades to my phono stage, custom plinth and new tonearm for my turntable, a mountain of rare 6AS7G-type OTL tubes in a box in my basement.....going to try and bury my desire to work on those things deep inside for a while lol.

I have more vinyl storage space now too, so obviously I will need to fill it ASAP :)
 
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May 7, 2021 at 7:59 PM Post #2,513 of 2,708

bcowen

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I THINK I am going to pump the brakes hard when this system is done. The sound I am getting is goosebump generating, that's the benchmark for me, so I'm good :D I'll probably make or buy some cool interconnects and stuff like that, I have a laundry list of tweaks that need to be made to the gear I've finished, so that's probably what I'll work on first. Then there is this SIT power amplifier, the HK54 A2 amplifier, upgrades to my phono stage, custom plinth and new tonearm for my turntable, a mountain of rare 6AS7G-type OTL tubes in a box in my basement.....going to try and bury my desire to work on those things deep inside for a while lol.

I have more vinyl storage space now too, so obviously I will need to fill it ASAP :)

All that extreme gorgeousness in the foreground, and then there's this hiding in the background:

1620431729138.png


Kind of like buying a Ferrari and filling it up with 80 octane gas. LOL! Of course if you just have accessory type stuff plugged into that, then nevermind. :smile:
 
May 7, 2021 at 8:09 PM Post #2,514 of 2,708

L0rdGwyn

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All that extreme gorgeousness in the foreground, and then there's this hiding in the background:



Kind of like buying a Ferrari and filling it up with 80 octane gas. LOL! Of course if you just have accessory type stuff plugged into that, then nevermind. :smile:

How dare you! I'll have you know that power strip is made of ivory and the wiring is silver-plated platinum...

But in all seriousness, that is a plane Jane, no internal filtering, no surge protection power strip, just wire and plugs, and it is very intentional :)

The other end is connected to a 2.5kVA MGE isolation transformer, wired for balanced power +60/-60VAC, and better than any filtering in terms of common mode noise rejection, so essentially everything in the system is connected directly to the output of the transformer in parallel. That is some ultra pure AC coming out of that crappy power strip LOL but I should probably get something that at least LOOKS sexier. All of the wiring of the system needs an upgrade, except for the speaker cables maybe, just hasn't been a priority with so many other things going on.
 
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May 7, 2021 at 8:39 PM Post #2,515 of 2,708

bcowen

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How dare you! I'll have you know that power strip is made of ivory and the wiring is silver-plated platinum...

But in all seriousness, that is a plane Jane, no internal filtering, no surge protection power strip, just wire and plugs, and it is very intentional :)

The other end is connected to a 2.5kVA MGE isolation transformer, wired for balanced power +60/-60VAC, and better than any power supply filtering in terms of common mode noise rejection, so essentially everything in the system is connected directly to the output of the transformer in parallel. That is some ultra pure AC coming out of that crappy power strip LOL but I should probably get something that at least LOOKS sexier. All of the wiring of the system needs an upgrade, except for the speaker cables maybe, just hasn't been a priority with so many other things going on.
LOL! I could tell by looking at it that it was ivory, but the switch looks kind of cheap. :stuck_out_tongue: :stuck_out_tongue:

I'm not one of those $200 outlet kind of guys***, but I do believe that good sockets with a firm grip on the plug do make a difference. I have a chassis similar to this one in the closet, just never got around to putting it together with some good sockets and wire because I haven't had a need for it (yet). It's all aluminum and pretty nicely machined for the money.

https://www.ebay.com/itm/274410580886?_trkparms=ispr=1&hash=item3fe4252b96:g:SIQAAOSwbDRe904g&amdata=enc:AQAFAAACgBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkY3FSd4Ad8xn3oRtkVexxrKNM3NDghHC%2F7TwsFiXvuz6ATSQz4fO1Rwv5OxQeMFRmOCP9860cfFq38kQekiU6t156tUL%2Fsw2mENSOYDA5bEHwW%2F95c4B8vkiY8EpZvAKt7%2FPvt3o%2FxmpaQaQLLZbHJmkQfMtXPkSqZ%2Bdlfm19OxDKJfVMo%2FzjcaIfRGPzFam3Z6WbMEy%2BQriUw0pGSvXzaLwhUJI427RqhTqr0EB628x0LW%2FpJY5KLrvJPX8zam5LxsXRTo18CoFWzWcwdYYHbA5TaacZsrzVHbhO3A3ta0PglLuVcJRGm38Q1C81d%2FmhgpQetphaVL%2FWErxdIS133D2Bn7iLVUYCOyK76ncX9xOgdAmPCbDkJS1NJ1GOW0jahTfFmxTG4hDtY38%2BivLgjGtGnHQFAnzNbKDarhR5xJb7JjkBXf0bunbe1GeZwwoxMeEiS6c54BwKKb9AT2jZA7Wvfy0RNO0cR5brCiwYsMtwwti%2FSrIrs4EtBR14lHFLbiXFDY1oJ18F6BEvBginQXYP%2FUTqj9duKtZizuPqwJOaF0wG2erwxzJ0YQt7ycOrVgdWXJaP6wgaeR%2B3y0LA47WheXXTVdABId6tzq0uL5UEMJZVhL27hKRtBLNOl7ONHdL2y7jddClKDJu2HVxwHeVEM%2B3HjU0daRbw8%2Fq5nlwyCYDJBNlIL85nFaphZSgrc80MYC%2B6RTetouXEWhMFJVQBV5MBcMlbmVBsB6XC8d3IIk7Z0PClWiHy3pL6kIkteYTVgdfLpdMrM1Ja5tuCTm9osqtMHiyaA0OY9Ya53Dk%3D|cksum:274410580886d2864b89d31e4b89ada391aa93ca838b|ampid:pL_CLK|clp:2334524

1620434183087.png



***I do have one high dollar Furutech outlet that I bought mostly just to satisfy my curiosity. It is very nicely constructed and supremely high quality (which it better be for the money), but sonically? If there's a difference between it and just a good quality Leviton or P&S outlet, it's beyond my hearing capability. :smile:
 
May 7, 2021 at 8:58 PM Post #2,517 of 2,708

L0rdGwyn

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LOL! I could tell by looking at it that it was ivory, but the switch looks kind of cheap. :stuck_out_tongue: :stuck_out_tongue:

I'm not one of those $200 outlet kind of guys***, but I do believe that good sockets with a firm grip on the plug do make a difference. I have a chassis similar to this one in the closet, just never got around to putting it together with some good sockets and wire because I haven't had a need for it (yet). It's all aluminum and pretty nicely machined for the money.

https://www.ebay.com/itm/274410580886?_trkparms=ispr=1&hash=item3fe4252b96:g:SIQAAOSwbDRe904g&amdata=enc:AQAFAAACgBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkY3FSd4Ad8xn3oRtkVexxrKNM3NDghHC%2F7TwsFiXvuz6ATSQz4fO1Rwv5OxQeMFRmOCP9860cfFq38kQekiU6t156tUL%2Fsw2mENSOYDA5bEHwW%2F95c4B8vkiY8EpZvAKt7%2FPvt3o%2FxmpaQaQLLZbHJmkQfMtXPkSqZ%2Bdlfm19OxDKJfVMo%2FzjcaIfRGPzFam3Z6WbMEy%2BQriUw0pGSvXzaLwhUJI427RqhTqr0EB628x0LW%2FpJY5KLrvJPX8zam5LxsXRTo18CoFWzWcwdYYHbA5TaacZsrzVHbhO3A3ta0PglLuVcJRGm38Q1C81d%2FmhgpQetphaVL%2FWErxdIS133D2Bn7iLVUYCOyK76ncX9xOgdAmPCbDkJS1NJ1GOW0jahTfFmxTG4hDtY38%2BivLgjGtGnHQFAnzNbKDarhR5xJb7JjkBXf0bunbe1GeZwwoxMeEiS6c54BwKKb9AT2jZA7Wvfy0RNO0cR5brCiwYsMtwwti%2FSrIrs4EtBR14lHFLbiXFDY1oJ18F6BEvBginQXYP%2FUTqj9duKtZizuPqwJOaF0wG2erwxzJ0YQt7ycOrVgdWXJaP6wgaeR%2B3y0LA47WheXXTVdABId6tzq0uL5UEMJZVhL27hKRtBLNOl7ONHdL2y7jddClKDJu2HVxwHeVEM%2B3HjU0daRbw8%2Fq5nlwyCYDJBNlIL85nFaphZSgrc80MYC%2B6RTetouXEWhMFJVQBV5MBcMlbmVBsB6XC8d3IIk7Z0PClWiHy3pL6kIkteYTVgdfLpdMrM1Ja5tuCTm9osqtMHiyaA0OY9Ya53Dk%3D|cksum:274410580886d2864b89d31e4b89ada391aa93ca838b|ampid:pL_CLK|clp:2334524

1620434183087.png


***I do have one high dollar Furutech outlet that I bought mostly just to satisfy my curiosity. It is very nicely constructed and supremely high quality (which it better be for the money), but sonically? If there's a difference between it and just a good quality Leviton or P&S outlet, it's beyond my hearing capability. :smile:

I'm not one of those guys either, but that aluminum chassis you linked looks great! Maybe I'll grab one and make the same thing, wire and sockets, but you know...not a piece of crap LOL. Fixing up the wiring situation is high on the to-do list once all the major components are settled. Could DIY some power cables and interconnects, but I sort of hate making cables...
 
May 7, 2021 at 9:26 PM Post #2,518 of 2,708

bcowen

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May 7, 2021 at 11:02 PM Post #2,519 of 2,708

Galapac

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375FF4E9-C1A6-42AD-93F1-CFF45EC79C4D.jpeg


That’s the key power strip there, must be hot as hell, lol.
The one to power them all...
 
May 7, 2021 at 11:53 PM Post #2,520 of 2,708

Ripper2860

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