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Old 7th September 2008, 05:19 PM   #21
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Are there any tubes in the board? Do you have a switch or jumper across the SW 1 terminals? If there are no tubes, and a jumper (or closed switch) your readings seem OK. The transformer voltage will be high with no load, so will the B+.

I would recommend removing the jumper, or opening (off) the switch for initial testing. The voltage at the yellow wires should be low or zero without tubes.

With all tubes in place the voltage at the yellow wires should be 430 to 480 volts.
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Old 7th September 2008, 05:55 PM   #22
cjkpkg is offline cjkpkg  United States
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OK - Brain fart time...I spent 18 hours in the air yesterday so I am still not thinking clearly....

No tubes, no jumper
yel 1 - 5.1
yel 2 - 0
red 1 415
red 2 415
red/yel - 0
green/yel - 2.3
green 1 - 6.3
green 2 - 0

With tubes and jumper
yel 1 - 547
yel 2 - 547
red 1 - 409
red 2 - 409
red/yel - 0
green/yel - 75
green 1 - 76
green 2 - 76

wall voltage today is 122.1

Thinking this through again, this now seems to make sense to me with no load...

One thing still eludes me...what is the purpose of the red/yel tap? after I got 0 volts in both situations I took an OHM reading and it read 0...

Thanks,
(sleepy) Carl
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Old 7th September 2008, 06:25 PM   #23
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Quote:
One thing still eludes me...what is the purpose of the red/yel tap? after I got 0 volts in both situations I took an OHM reading and it read 0...
It is the center tap on the high voltage winding and it is connected to ground therefore it should read zero ohms to ground.

547 volts sounds too high if the output tubes are in place. Check the voltages at the end of R17 and R27 that is closest to the rear of the PC board. It should be about 30 volts depending on the output tube used.

Quote:
I spent 18 hours in the air yesterday so I am still not thinking clearly.... (sleepy)
Please do not play with electricity if you are not totally alert. 547 volts can really ruin your day. I routinely cease my experimentation at 10 PM since I know I am not as alert after 10, and I have been doing this for 40 years.
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Old 7th September 2008, 09:13 PM   #24
cjkpkg is offline cjkpkg  United States
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George, you are 100% correct. I have called it a day.

I did take one last reading across R17 and R27 and there is zero volts indicated. I guess I have a cold solder joint somewhere upstream...there is also zero volts on R18 and R28...

Would there be a common culprit for this symptom?

I will put off trying to trace it down till tomorrow when I am of more sound mind...
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Old 8th September 2008, 01:25 AM   #25
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Quote:
Would there be a common culprit for this symptom?
This indicates that the B+ is not getting to the output tubes. Are the OPT's in place and connected correctly? If you are using triode mode, do you have the jumper between the right most terminals of the OPT connector?

Check for voltage on all three terminals of the T3-PRI connector. You already indicate that there is no voltage or R28 which is the center terminal. There should be voltage on the left terminal since it comes through the board. There should be voltage on the right terminal. It comes through the OPT. If there is no voltage, check the OPT wiring. The center terminal gets powered through the OPT in UL mode. It should be jumpered to the right terminal in triode mode.

T2-PRI works the same way.
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Old 9th September 2008, 02:56 AM   #26
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Quote:
Originally posted by Ty_Bower


I've been thinking about intentionally trying a 12AU7 in the driver tube position.

Why would I want to do this? Well, the 12AT7 just has a lot more gain than I feel like I really need.
The JJ ecc99 is doing great in my amp driving 6550s. I set the ccs current resistor at 150 Ohms so its running at 22 mA or so plate current. I haven't measured it (or anything else) yet... just been using it every day for the last few months

The JJ ecc99 was designed specifically as an audio power tube driver, and it is a very linear tube with a much lower mu than a 12at7.

Dave
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Old 21st September 2008, 01:22 AM   #27
cjkpkg is offline cjkpkg  United States
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OK, after a couple of weeks of other projects taking priority I have finally done a test run with the Simple SE...

All I can say is WOW...it is dead silent. Now it is not as "loud" as the yamaha CA-810 but when I run it through the CA-810 acting as a pre-amp the Simple SE really shines.

I am running the cheap chinese 6L6GC tubes...I am really excited to try some KT88's...or mayber some EL34's...

I have been listening to the Simple SE through the Yamaha CA-810 as pre-amp and Technics SL-1300 Genesis - The Lamb Lies Down on Broadway and it sounds really nice...maybe the best descriptive word is "genuine"...

very impressed with the Simple SE...

Carl
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Old 22nd September 2008, 12:34 AM   #28
cjkpkg is offline cjkpkg  United States
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I hooked the Simple SE up in UL mode today and had a listen. I must say that the tube amp just brings out something that all the solid state suff before it just could not negotiate...

Tubes rule...
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Old 22nd September 2008, 02:00 AM   #29
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Two posts since you got it running, and no photo of the finished amp? Please, don't keep us waiting any longer!

Quote:
Originally posted by cjkpkg
I am running the cheap chinese 6L6GC tubes...I am really excited to try some KT88's...or mayber some EL34's...
I picked up this set of Shuguang 6L6GC. They were dirt cheap. I haven't tried them yet in my Simple SE. I'd be interested to know what you think of yours...

Click the image to open in full size.
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Old 22nd September 2008, 12:13 PM   #30
cjkpkg is offline cjkpkg  United States
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I still have to finish the base cabinet so no pics yet...

The 6L6GC's have a great sound. I sampled a little rock, electronic, and downtempo/chill from my ipod and it all sounded really warm. I was picking out sounds that I have never heard from my car stereo or my home theater receiver.

I cant wait to get the chassis finished!
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