Well I have decided to take the plunge into building a tube amplifier after finishing up my Class D amplifiers. After looking into some of the budget kits, S5 brand, I settled on a TubeLab SimpleSE. In the end it will cost a bit more but I also like being able to control what parts are being used. I have read through many of the build logs here and gathered ideas for parts and tips on what to use in my build. For some reason there is just something about the sound and glowing tubes that keeps drawing me back to these. I figure diyaudio could use just one more TubeLab SimpleSE build log.
Parts List:
All small components(resistors, capacitors, etc) will be the same values as seen on TubeLabs parts list as seen HERE
Allied 6K7VG Power Transformer
Triad C-14X Choke
Edcor GXSE15-8-5K Audio Transformer
Alps RK27 50k Potentiometer
Diversitech 80uf 370vac Motor Run Capcitor
Parts Needed:
2 - 10k 3W Metal Oxide Film Resistor
1 - 150k 3W Metal Oxide Film Resistor
5AR4 Rectifier Tube(solid state will be omitted from this build, read too many issues with the FRED diodes)
12AT7 Input Tube
Power Tubes
Switches
.22uf Auricaps
Chassis(going to build my own)
Questions:
- Any Recommendation for a pair of power output tube that will work good with my set up?
- As I was looking at switches it dawned on my that they need to be able to handle the current. The majority I see are able to handle 125vac, I figure that will be fine for the mains switch but how about the UL/Triode switch and cathode feedback switch?
Also if anyone has the three resistors in my parts needed list laying around I will buy them off you. Mouser has them on order and I have no idea when they will be back in.
Well now just have to wait for the board to arrive so that I can get to soldering.
Parts List:
All small components(resistors, capacitors, etc) will be the same values as seen on TubeLabs parts list as seen HERE
Allied 6K7VG Power Transformer
Triad C-14X Choke
Edcor GXSE15-8-5K Audio Transformer
Alps RK27 50k Potentiometer
Diversitech 80uf 370vac Motor Run Capcitor
Parts Needed:
2 - 10k 3W Metal Oxide Film Resistor
1 - 150k 3W Metal Oxide Film Resistor
5AR4 Rectifier Tube(solid state will be omitted from this build, read too many issues with the FRED diodes)
12AT7 Input Tube
Power Tubes
Switches
.22uf Auricaps
Chassis(going to build my own)
Questions:
- Any Recommendation for a pair of power output tube that will work good with my set up?
- As I was looking at switches it dawned on my that they need to be able to handle the current. The majority I see are able to handle 125vac, I figure that will be fine for the mains switch but how about the UL/Triode switch and cathode feedback switch?
Also if anyone has the three resistors in my parts needed list laying around I will buy them off you. Mouser has them on order and I have no idea when they will be back in.
Well now just have to wait for the board to arrive so that I can get to soldering.
Thanks for the reply...although I dont know If I am ready to spend the cost of what it took to build the amp on a pair of tubes just yet. I have read others using E34L tubes and KT88 tubes. I suppose I could just give one of those two a try since they seem to be some what affordable and will introduce me to tubes while keeping my self on some what of a budget.
2A3's are more suited for the tubelabSE, not the simpleSE.
They are 4-pin DHT's; you'll need octal power tubes.
As already mentioned, EL34's or KT88's are a good place to start. You can also run 6V6/6L6/6L6GC's among others. In general, EL34's have great mids/vocals, KT88's have a little more bass, and slightly more power output. KT88's require a little more power out of the power transformer than EL34's.
Here is the link to Tubelab's tube data page:
http://www.tubelab.com/AssemblyManualSimpleSE/TubesAndTransformers_SSE.htm
You could also use NOS 6L6's (no GC) as they are affordable but have lower power output than the GC variety.
If you are on a budget, Tubelab George has had good luck with the chinese 6L6GC's.
They are 4-pin DHT's; you'll need octal power tubes.
As already mentioned, EL34's or KT88's are a good place to start. You can also run 6V6/6L6/6L6GC's among others. In general, EL34's have great mids/vocals, KT88's have a little more bass, and slightly more power output. KT88's require a little more power out of the power transformer than EL34's.
Here is the link to Tubelab's tube data page:
http://www.tubelab.com/AssemblyManualSimpleSE/TubesAndTransformers_SSE.htm
You could also use NOS 6L6's (no GC) as they are affordable but have lower power output than the GC variety.
If you are on a budget, Tubelab George has had good luck with the chinese 6L6GC's.
Try alternate part number MOS3CT631R103J for the 10k 3W resistor.
For the 150k 3W power supply resistor, it would be fine to substitute a 160k part, so use 283-160K-RC.
For the 'first power test', use something cheap and current production. I like my JJ E34L more than the Chinese 6L6GC tubes, and they're only $10 more per pair. Don't bother with the 'Blue Glass' option, it's really not as cool as it sounds.
Rick
For the 150k 3W power supply resistor, it would be fine to substitute a 160k part, so use 283-160K-RC.
For the 'first power test', use something cheap and current production. I like my JJ E34L more than the Chinese 6L6GC tubes, and they're only $10 more per pair. Don't bother with the 'Blue Glass' option, it's really not as cool as it sounds.
Rick
The poster stated that he was building a Simple SE with most of the components already chosen. The Simple SE is a PC board based SE amplifier that uses octal output tubes. The choice of output tube is restricetd to the ones you don't like. Countless people have used the E34L, EL34, 6P3S, 6L6GC, KT88 and 6550 in SE HiFi amps including the Simple SE. These people seem happy with their amps. Yes you can get a more detailed sound from a mono plate 2A3, but you will need premium parts (especially OPT's) to get the most out of those tubes. The OPT's are already chosen here.
6L6 types that are not of the GC variety are not recommended here. The Allied transformer yields a B+ voltage around 460 volts, well above the maximum for a 6L6GB or GA and it will peel the paint off of the old metal ones!
What do you use? Any of the tubes mentioned above will work. I have two amps, one uses JJ EL34's. It has the most detailed sound, but gives up a bit of bass. There are several reports of reliability issues with some batches of JJ tubes especially their 5AR4's. I have not seen this myself, but my tubes are all about 4 years old. I have also had goos luck with Shuguang and Valve Art EL34's. The other amp used Electro Harmonix KT88's. These tubes are absolutely bulletproof and crank out the best bass of any tube that I have tried in the Simple SE. It does give up some detail though. I have used EH 6550's (same tube, different #) Shuguang and Valve Art KT88's (a little less bass). There are several 6L6GC type tubes that will work good. The sound is in between the EL34 and the KT88. The Shuguang or Sino 6L6GC and 6L6GCR (round) are the cheapest of the bunch. I use them for testing out new amps because they are hard to kill and don't sound bad. They can sometimes be found for as little as $5 each. My favorite is the "coke bottle" version (AES has them for $7.95). Chinese and Russian KT66's are another good 6L6 type.
Don't mean to hijack - but whilst resistors are being discussed....
R2 (150Kohm 3W) is a bleeder resistor right?
Assuming B+ at 500V for worst case dissipation=
Current flow would be 3.3mA for a power of 1.6W
For the situation of 2 paralleled 300K 2W resistors each will carry 1.7mA for a power of 0.8W each.
Obviously if one of the 300K resistors failed, the remaining should be fine.
The value of R2 - this just needs to be large enough to not interfere with the circuit, but also small enough to drain the caps adequately. If a larger value used - say a single 2W 300Kohm, the caps would just take longer to drain.
Is this correct, or have I missed something really important?
Lee
R2 (150Kohm 3W) is a bleeder resistor right?
Assuming B+ at 500V for worst case dissipation=
Current flow would be 3.3mA for a power of 1.6W
For the situation of 2 paralleled 300K 2W resistors each will carry 1.7mA for a power of 0.8W each.
Obviously if one of the 300K resistors failed, the remaining should be fine.
The value of R2 - this just needs to be large enough to not interfere with the circuit, but also small enough to drain the caps adequately. If a larger value used - say a single 2W 300Kohm, the caps would just take longer to drain.
Is this correct, or have I missed something really important?
Lee
Yep, just picked up a pair of the Chinese coke bottle 6L6GC as you have suggested and also George. Pretty good value and not going to break my heart if something happens to them on the first try of the amp...which I don't for see any issues but you never know.boywonder said:
I think I will grab one of these resistors or else parallel a pair of 2w 300k ohm resistors to get the same effect.rkevans said:
Good luck to you as well. Let me know how your first start up goesastrodog said:I've had problems sourcing any 3W resistors at all in this country.... so am going to parallel a pair of 2W resistors in place to give an equivalent 4W resistance instead.....
Good luck with the build, my simpleSE kicks off in a week or so.....
Thanks for the detailed answer George. I decided to go with a pair of the Chinese 6L6GCs and a pair of JJ E34L.tubelab.com said:
Now just to find some switches that I like and I am all set! Any one have any input on the switch voltage rating. I wasn't sure how much would be flowing into them from the cathode feed back or the ul/triode switch terminals.
Experience with Simple SE and 6L6 varieties
(a) strongly agree with George on the AES Chinese ($8) tubes; they seem to stand-up well in comparison to NEW Tungsol and JJ 6L6GCs, for about half price. I have take to using one of my Simple SEs as the "entertainment center" amp, and I usually leave the Chinese coke bottles in there with a JJ 5AR4 rectifier for use with the TV or rock & roll.
For detailed stuff (any classical, female vocals, or say Ella and Louis, playing right now), I switch to one of the following:
(b) used NOS 6L6GCs; for example I bought two Heathkit regulated power supplies, both of which had GE 6L6GCs which tested great. I replaced those with the $8 Indestructo Chinese 6L6GCs from AES in the power supplies (work great) and sequestered the GEs for audio.
Absolutely spectacular with the Simple SE circuit; I use the 5K Edcors wired ultralinear. Cathode bias resistor is 500 ohms. Dissipation is about 29-point-something Watts, I recall. I think it sounds like a cross between a 2A3 SE and an ultralinear El 84 PP amp, e.g. a Dynaco ST-35. Considering the Edcors are $20 apiece, it's shockingly good.
I understand that not everybody likes the tone of the untralinear connection, but I am a real devotee; won't build a "normal 3-wire" PP anymore, for example, just sounds muddled to me.
(c) Alternately, by using a 5R4-type rectifier tube and a relatively higher resistance choke (about 150 ohms DCR, IIRC) I can get the B+ down just low enough with the Allied power transformer (very low 400s) to use 5881/6L6WGBs. [still too hot for "regular" 6L6s]
This is one of my favorite tube-types, especially the NOS Tungsols.
If you buy used/"tested new" singles (not matched pairs; you don't need them for SE of course!) you can sometimes get them on e-Bay for about the same as the new Eastern Bloc tubes (~$15-16 each). Of course I've lost a lot of auctions this way, too. Qu'est sera sera.
No quite the UMPH of the GCs of course, but crisp clean and mellow. Female vocals are particularly good. I think I like them better than 6V6GTAs or 6BQ6GAs (the top-cap ones, AKA secret excellent 6V6 clones) which is saying something.
I recall that I bias them up right at the limit (23 W dissipation? I think that's a 560 ohm bias resistor) and they sound really sweet.
One last thing: MOUSER sells a single pin screw terminal which solders right into the bias resistor holes, and which makes rebiasing REALLY clean and easy. It's Mouser 534-8730 MINI BINDING POST at $0.47 each (real expensive for what it is, but priceless after you have switched bias resistors a couple of times). STRONGLY recommended.
(a) strongly agree with George on the AES Chinese ($8) tubes; they seem to stand-up well in comparison to NEW Tungsol and JJ 6L6GCs, for about half price. I have take to using one of my Simple SEs as the "entertainment center" amp, and I usually leave the Chinese coke bottles in there with a JJ 5AR4 rectifier for use with the TV or rock & roll.
For detailed stuff (any classical, female vocals, or say Ella and Louis, playing right now), I switch to one of the following:
(b) used NOS 6L6GCs; for example I bought two Heathkit regulated power supplies, both of which had GE 6L6GCs which tested great. I replaced those with the $8 Indestructo Chinese 6L6GCs from AES in the power supplies (work great) and sequestered the GEs for audio.
Absolutely spectacular with the Simple SE circuit; I use the 5K Edcors wired ultralinear. Cathode bias resistor is 500 ohms. Dissipation is about 29-point-something Watts, I recall. I think it sounds like a cross between a 2A3 SE and an ultralinear El 84 PP amp, e.g. a Dynaco ST-35. Considering the Edcors are $20 apiece, it's shockingly good.
I understand that not everybody likes the tone of the untralinear connection, but I am a real devotee; won't build a "normal 3-wire" PP anymore, for example, just sounds muddled to me.
(c) Alternately, by using a 5R4-type rectifier tube and a relatively higher resistance choke (about 150 ohms DCR, IIRC) I can get the B+ down just low enough with the Allied power transformer (very low 400s) to use 5881/6L6WGBs. [still too hot for "regular" 6L6s]
This is one of my favorite tube-types, especially the NOS Tungsols.
If you buy used/"tested new" singles (not matched pairs; you don't need them for SE of course!) you can sometimes get them on e-Bay for about the same as the new Eastern Bloc tubes (~$15-16 each). Of course I've lost a lot of auctions this way, too. Qu'est sera sera.
No quite the UMPH of the GCs of course, but crisp clean and mellow. Female vocals are particularly good. I think I like them better than 6V6GTAs or 6BQ6GAs (the top-cap ones, AKA secret excellent 6V6 clones) which is saying something.
I recall that I bias them up right at the limit (23 W dissipation? I think that's a 560 ohm bias resistor) and they sound really sweet.
One last thing: MOUSER sells a single pin screw terminal which solders right into the bias resistor holes, and which makes rebiasing REALLY clean and easy. It's Mouser 534-8730 MINI BINDING POST at $0.47 each (real expensive for what it is, but priceless after you have switched bias resistors a couple of times). STRONGLY recommended.
Re: Experience with Simple SE and 6L6 varieties
I used these all over my Tubelab SE and they work great. Someone on thos forum tipped me off to them...maybe it was you. If so, thanks!
I also used them for the cathode resistors for the Simple SE. A little tip: for those, I made a "fixture" out of a bent paper clip so that the posts leaned back in the somewhat over-sized holes. this made it easier to slip the legs in. Just watch the clearance with the caps next door.
hareynolds said:
I used these all over my Tubelab SE and they work great. Someone on thos forum tipped me off to them...maybe it was you. If so, thanks!
I also used them for the cathode resistors for the Simple SE. A little tip: for those, I made a "fixture" out of a bent paper clip so that the posts leaned back in the somewhat over-sized holes. this made it easier to slip the legs in. Just watch the clearance with the caps next door.
Thanks for the tip on the binding post. Too bad I already soldered in those resistors but if I do decide to change them out the binding posts will be put in place. I am going to add those to my next order. Now I was wondering would it be smart to use these for the coupling capacitor in case I ever wanted to try out other caps? On my class d amps I have always soldered these and I would think a good solid connection would be favorable.
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