The XPWR033 - 760VCT @ 200mA, 6.3V (No CT) @ 5A, 5V @ 3A is probably close to the Allied unit since the Allied is really a Hammond, and they always put out too much voltage (compared to their specs). Use 500 volt rated electrolytics for C1 and C2 since your B+ voltage will be near 450 volts. I have run a SimpleSE on a 800 VCT Antek toroid and it really cranked but the B+ was 520 volts with SS rectifiers which is too much for common electrolytics. The 820 VCT transformer would be just too much. Even with HV caps, the tubes themselves would be smoking.
I have used chokes from 5 to 10 Henries at 175 mA or more. The DC resistance should be from 50 to 200 ohms. A lower resistance results in a higher B+ voltage. I usually use the Triad C-14X because it is cheap, but it is ugly, so I hide it under the chassis. The Hammond 193H or 193J can be used also.
For the cap I use a 50 to 100 uF 370 VAC (or higher) motor RUN cap. They will handle over 500 volts on DC. I got some 100 uF 370 VAC ASC caps on ebay cheap, but the seller has no more. The same seller has 80 uF 500 VAC motor RUN caps for cheap but they are not ASC brand. Other builders have used them with good results. Look at auction # 170078126766. Do NOT use a motor START cap. They are not rated for continuous use.
I have used chokes from 5 to 10 Henries at 175 mA or more. The DC resistance should be from 50 to 200 ohms. A lower resistance results in a higher B+ voltage. I usually use the Triad C-14X because it is cheap, but it is ugly, so I hide it under the chassis. The Hammond 193H or 193J can be used also.
For the cap I use a 50 to 100 uF 370 VAC (or higher) motor RUN cap. They will handle over 500 volts on DC. I got some 100 uF 370 VAC ASC caps on ebay cheap, but the seller has no more. The same seller has 80 uF 500 VAC motor RUN caps for cheap but they are not ASC brand. Other builders have used them with good results. Look at auction # 170078126766. Do NOT use a motor START cap. They are not rated for continuous use.
George (& others),
Thanks for all of your extremely helpful input - most of the items are currently on their way to me at the moment. Is there any sort of machining template for the circuit board? (Screw holes and cutouts for tube sockets?)
I'm going to be constructing a chassis and I have access to a machine shop at school, so I figure I'll have an easier time making holes the exact size I want if I have center drill locations.
Thanks!
Thanks for all of your extremely helpful input - most of the items are currently on their way to me at the moment. Is there any sort of machining template for the circuit board? (Screw holes and cutouts for tube sockets?)
I'm going to be constructing a chassis and I have access to a machine shop at school, so I figure I'll have an easier time making holes the exact size I want if I have center drill locations.
Thanks!
Any input on these motor RUN caps? Item # 180205364432
They are the same physical size and price, but higher (100uF) value.
Additionally, how much effect does the bigger choke have? Is the basic one good enough? Up to this point, I've been springing for all better quality (read more expensive) components, so I don't really want to cheap out on the last few things if they will make a difference.
They are the same physical size and price, but higher (100uF) value.
Additionally, how much effect does the bigger choke have? Is the basic one good enough? Up to this point, I've been springing for all better quality (read more expensive) components, so I don't really want to cheap out on the last few things if they will make a difference.
If it is any help, I think I made a template by taping the PCB to a sheet of paper and used a pencil to mark the screw holes through the holes on the PCB. For the tube centres, I made a pencil mark through the PCB for each hole for the tube socket legs and then used a ruler and pencil to join the opposite marks. This gave a "wagon wheel" type pattern with the lines all crossing in the centre point of the tube socket position. Remember thinking at the time that a small hole in the PCB at the centre of each tube socket would have made producing a template off the PCB easier, but no big deal.
Hope this helps,
Chris
Hope this helps,
Chris
I'd appreciate any suggestions for the rectifier tube, given the additional 10V on the B+ from my transformer. I know that different tubes can be run (the 5AR4/GZ34 seems to be the standard for the SimpleSE from what I can tell) and that some have a bigger drop, so that might be advantageous for me.
Any suggestions for style/gauge/etc of hookup wire and type of coax for inputs are appreciated as well. I've heard that the MIL spec wire is well liked, but what gauge is commonly used?
Once I finalize the decision on the RUN cap and the rectifier, I will be set. I've also decided to use a NOS 12AT7 since the price is very reasonable and I've heard good things about the Sylvania and Philips from a few sources.
My Edcor's are on their way, got the tracking on Friday so hopefully they'll be here by mid week. I need to get the last few parts on order so I can hear my amp soon! I've got a quad of Shuguang Coke Bottle 6L6GCs to use as my initial set of inexpensive tubes upon fire up. I'm eventually thinking of trying a few different output tubes to see which ones I like best.
This project certainly has been a learning experience!
Any suggestions for style/gauge/etc of hookup wire and type of coax for inputs are appreciated as well. I've heard that the MIL spec wire is well liked, but what gauge is commonly used?
Once I finalize the decision on the RUN cap and the rectifier, I will be set. I've also decided to use a NOS 12AT7 since the price is very reasonable and I've heard good things about the Sylvania and Philips from a few sources.
My Edcor's are on their way, got the tracking on Friday so hopefully they'll be here by mid week. I need to get the last few parts on order so I can hear my amp soon! I've got a quad of Shuguang Coke Bottle 6L6GCs to use as my initial set of inexpensive tubes upon fire up. I'm eventually thinking of trying a few different output tubes to see which ones I like best.
This project certainly has been a learning experience!
I have 100uF 370 VAC caps in my amp. Thet were made by ASC but don't seem to be available any more. These should work well.
If you want to lose about 10 volts, use a 5V4. I like the sound of the 5AR4, and they are easier to find. 5U4's can be used but they heat up to fast allowing the B+ to come on before the output tubes are ready. I have had bad luck with the military 5R4GYB. Two out of two have blown up.
I think that the Shuguang coke bottle 6L6GC's can take 450 or more volts without any problems. I still have my first pair, and they were used when I got them. People who know me understand what I do to some tubes to find their limits (note, I don't abuse rare or valuable tubes). Mine have seen 525 volts and are still alive.
Antique Electronics Supply used to advertize the coke bottle 6L6GC by saying "We could not blow up this tube no matter how hard we tried." I took this as a challenge. The picture below shows one of my attempts. They are running at 44 watts of dissipation, about twice what most people run. This picture is 4 years old. This pair of tubes are STILL ALIVE today. I use them in most every experiment and new build for testing.
Attachments
From Antique Electronics Supply's web site:
Chinese 6L6GC $7.95
We tried to blow this one up, but could not!!!
This is a current add referring to the new slim one.
The newer slimmer ones don't seem to shed the heat as good as the coke bottle shaped ones do. Both are fine at the published ratings, but those of us who take those ratings as mere suggestions find the coke bottle shaped ones good for 1 or 2 additional watts of dissipation.
The coke bottle shaped tubes disappeared about two years ago. Now they seem to be in stock at several places. One distributor offered me 100 at $4 each. I don't need that many, especially if you can't blow it up.
Chinese 6L6GC $7.95
We tried to blow this one up, but could not!!!
This is a current add referring to the new slim one.
The newer slimmer ones don't seem to shed the heat as good as the coke bottle shaped ones do. Both are fine at the published ratings, but those of us who take those ratings as mere suggestions find the coke bottle shaped ones good for 1 or 2 additional watts of dissipation.
The coke bottle shaped tubes disappeared about two years ago. Now they seem to be in stock at several places. One distributor offered me 100 at $4 each. I don't need that many, especially if you can't blow it up.
I'm excited to hear how they sound. I believe you said in the past they actually have pretty decent sound, and given the price that's not a bad deal at all. Given the stock SimpleSE bias, how many watts output should be expected?
Do they exhibit the fluorescence like the EH KT88's? I'm still considering a pair of those and/or a pair of the Tung-Sol 6550's.
For that matter, can anyone comment on how long any of these tubes need to break in?
Do they exhibit the fluorescence like the EH KT88's? I'm still considering a pair of those and/or a pair of the Tung-Sol 6550's.
For that matter, can anyone comment on how long any of these tubes need to break in?
Well, tough or not, the little chinese 6L6s are not going to hang with KT88s or 6550s from EH or TS as far as audio quality goes. It's just not going to happen. In that case look at the Shuguang KT66, which is a very fine tube, just very large, which is cool, but something you need to allow for.
While all tubes sound somewhat different, I find many of the new production tubes to be of excellent quality. I am extremely pleased with my new Tung Sol 6550s... and plan on picking up a set of the EH KT88s soon... and many sites review those as the best current production audio tube, though I personally would be hesitant to label any one tube "the best." The nice thing about tube rolling is, they all sound pretty dang good! So, no matter what tube, the music should still be rocking.
As for power output with the SimpleSE, Tubelab is the guy to ask about that...
While all tubes sound somewhat different, I find many of the new production tubes to be of excellent quality. I am extremely pleased with my new Tung Sol 6550s... and plan on picking up a set of the EH KT88s soon... and many sites review those as the best current production audio tube, though I personally would be hesitant to label any one tube "the best." The nice thing about tube rolling is, they all sound pretty dang good! So, no matter what tube, the music should still be rocking.
As for power output with the SimpleSE, Tubelab is the guy to ask about that...
The Chinese 6L6GC's will make about 4 watts in triode and 9 or 10 in UL mode, assuming 440 (or thereabouts) B+ and a 5K ohm load. The tubes that I have do not have any blue glow.
I don't know, all of the tubes that I have are well used. I pulled the tubes shown above out of a Bandmaster.
The 6L6GC's do not sound as good as the more expensive tubes, but they are the best $8 tube I have heard. I got all of mine for $5 or less. I got some used EH KT88's and 6550's for $10 each. These have a markedly better sound than the 6L6GC's. They make about 5 or 6 watts in triode and 12 or 13 in UL in the same amp with no other changes. All of mine (8) glow blue. The glow flashes with the bass on loud music (Pink Floyd comes to mind).
The EL34 (I am using JJ's) make the most power 6 watts in triode, 14 in UL and do the best on simple detailed music, but they don't rock like the EH KT88's. The KT88's actually sound louder.
So which tubes do you use? I have a bunch to choose from, but I find that I use the EL34's and the KT88's for just about everything.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.