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Summer is here - little tubes go in Simple SE

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Summer is here in Arkansas, and to save on heat in the living room, where the Simple SE runs whenever someone is home, I've rigged it up for the little tubes.

Right now I'm running GE 6K6GT's and when I want to really save on heat, I go with 6G6G's, which sound surprisingly good within their limitations. After a trip to the warehouse the most powerful tube I now have at home is 5881 (excepting a pair of the cobalt blue Tesla EL34's - my wife really likes the cobalt color, so what can you do :)).

If you can use the little tubes in your Simple SE - give it a try. They sound great, better than the big ones, I think, although when set up for low power they sometimes lack the deep bass extension of some of the more powerful tubes, but they consume / radiate a fraction of the heat.

Win W5JAG
 
There are a few little power pentodes, i.e. 6F6, 6G6, 6K6, 6M6 (never seen one of these). These have the 7S pin out that is compatible with the Simple SE.

And little beam pentodes like 6DG6GT/6W6GT, 6V6, 6U6, and 6Y6 that have the 7AC pin out for the simple SE.

There is also a small Russian power pentode whose number escapes me at the moment (6S6S?) that turns up frequently on ebay. If you search "6F6" these almost always turn up. There may be other eastern bloc tubes as well.

All come in multiple styles like metal, small bulb GT style, and shoulder G style, except 6G6G, which I have only ever seen in a miniature shoulder shaped bottle, although the books list a GT style.

There may be others. They kind of fall into two groups: the 200 volt bunch: 6G6, 6U6, 6W6, 6Y6; and the 300 volt bunch like 6F6, 6K6, and 6V6.

My power transformer does have dual secondaries where I can easily run the little 200 volt tubes (mostly) within their ratings, but I've run 6K6, 6F6, 6W6, 6V6, the Russian tube, and even 6G6G in the low mid 300's without issue. A 5W4 has the maximum voltage drop of the rectifiers compatible with the Simple SE, followed by the american 5Y3, if you want to try some of these. The 5Y3 marketed by Sovtek is a nice tube but it's not a 5Y3 and has a much smaller voltage drop - it's more like a low current 5V4.

I'll post a pic or two later tonight.
 
OK, a pic of the Simple SE with the Russian power pentodes sitting in it, and a shot of some of the "little" tubes with an EL34 for reference.

From the left: EL34, 6S6S, 6G6G, 6BQ6GTB, 5881, 6K6GT, 6W6GT, and 5992.

Win W5JAG
 

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What's a 6K6? Is that like a 6V6, only smaller?

The 6K6 is about the same size as the 6V6GT, except it is a true pentode where the 6V6GT is a beam tetrode. They sound different.

How did you do the B+? Do you have multiple taps off the high voltage secondary?

In my case I built a second amp. I used an Allied 6K56VG power transformer. It gives a B+ of 310 to 330 volts depending on tubes. I am still using a 5AR4. I use a set of Edcor XSE15-8-5K OPT's since these amps only make 2 WPC. The Edcor is great at this power level.
 
Hi.

I'm going to build the SSE and I would like to test the JJ 6V6S , I read in this forum that the sound is low power but wonderful , I will use the EDCOR XPWR010 (375-0-375) for a big tubes and I would like to know if I can use this transformer for the JJ , with a cathode resistor of about 1.3-1.5K and 5U4GB to lower the voltage about 15-20v (The JJ seems to support 450v).
I would not like to blow the tubes and I will not buy another transformer for the JJ.

Thanks.
 
A 5W4 or 5Y3 would put your B+ around 410-415 volts with a 375-0-375 transformer, and is what I would use.

JJ claims their 6V6SS will stand 450 volts in triode and 500 in pentode. By the time you subtract your cathode voltage, you should be at about 390 volts across the tube, so you will probably be OK with the JJ, at least for awhile, assuming their specs are not inflated. The EH claims to take high voltage, so you might try that one as well.

1.2K is probably a reasonable starting point for a cathode resistor until you can take some measurements.

As Tubelab has said, anytime you go where the designer never intended, some experimentation is required. Let us know how it works.

Win W5JAG
 
I don't know your comfort level with experimenting, but a choke input power supply is another means to the end. That would substanially lower your B+ voltage and put it much closer to where it needs to be for 6V6's.

IIRC, Ty_Bower modified his SSE with an extra choke to run 6L6GA's - you could probably search under his name and find his thread on it.

Win W5JAG
 
Hi W5JAG and Ty_Bower.

I'm an amateur and so far not want to get with serious experiments , I'm in the process of assembling the parts , I'll go with the first option changing 5U4 for 5Y3 , and my idea seemed not so bad , this is the first amp that I build and the comments I read it seems the bomb.

Thanks.
 
Summer is here in Arkansas, and to save on heat in the living room, where the Simple SE runs whenever someone is home, I've rigged it up for the little tubes.

Right now I'm running GE 6K6GT's and when I want to really save on heat, I go with 6G6G's, which sound surprisingly good within their limitations. After a trip to the warehouse the most powerful tube I now have at home is 5881 (excepting a pair of the cobalt blue Tesla EL34's - my wife really likes the cobalt color, so what can you do :)).

If you can use the little tubes in your Simple SE - give it a try. They sound great, better than the big ones, I think, although when set up for low power they sometimes lack the deep bass extension of some of the more powerful tubes, but they consume / radiate a fraction of the heat.

Win W5JAG


I guess you could use a chip amp for the summers ............. :D
 
6v6

Hi W5JAG and Ty_Bower.

I'm an amateur and so far not want to get with serious experiments , I'm in the process of assembling the parts , I'll go with the first option changing 5U4 for 5Y3 , and my idea seemed not so bad , this is the first amp that I build and the comments I read it seems the bomb.

Thanks.

I've been running the jj 6v6s' with a PA060 transformer (same tranny as in st-70, 360-0-360v) for about 8 months with no problem whatsoever. Sounds awesome! The b+ is around 430v. I think I am using a 1300 ohm cathode resistor or therabouts. I'm using the same rectifier that tubelab recommends-nothing special. I'd stay away from the 375-0-375 transformer though. At most go with a 360, but really you can go much lower if you plan on using 6v6's.
 
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