I have all the parts for the Simple P-P kit. The last batch of bagged up kits have been sold, but I just got an order so I will be bagging up more this weekend.
The Simple SE kit is a problem since 500 volt caps are impossible to get right now. I got some of the Illinois Capacitor parts, but I am hesitant to use them until I play with them for a while. They got a poor reputation due to failures in Fender guitar amps. The mounting scheme in a Fender guarantees a short life since they sit above the tubes, so it may not apply here. The IC's are only 85C rated.
It is totally possible, and some believe better to eliminate the electrolytics from the power supply and use only motor run caps. In fact one SSE builder made his entire amp without any electrolytics. 40 uF for the first cap is good, and I have used everything from 100 uF to 600 uF for the second cap. The 600uF was total overkill and hard on the rectifier tube, but I got some cheap on Ebay.
The parts kit includes only the parts needed to populate the PC board. You will still need the chassis, the parts mounted to the chassis, tubes and transformers.
600 uF second cap
"I have used everything from 100 uF to 600 uF for the second cap. The 600uF was total overkill and hard on the rectifier tube, but I got some cheap on Ebay."
George, I also picked up those 600 uF monsters, I was thinking they might boost the bass response of my SSE but was concerned how hard it would be on my rectifier tube. Did you prefer it in the circuit?
"I have used everything from 100 uF to 600 uF for the second cap. The 600uF was total overkill and hard on the rectifier tube, but I got some cheap on Ebay."
George, I also picked up those 600 uF monsters, I was thinking they might boost the bass response of my SSE but was concerned how hard it would be on my rectifier tube. Did you prefer it in the circuit?
Ahhh, you must have missed the PCB ordering tab PCB_ordering Easy enough to do...
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hi,
i am putting together the goods for my first amp build (greenhorn and then some) pcb and parts kit are ordered.
after a lot of digging i have a satisfactory quote from a uk supplier for the following:- Hammond 372JX, 2 x Hammond 1650 FA, EL84 sovtek matched quad, 5U4 GT, pair 12AT7 (ECC 81)
fit for purpose? please advise.
thanks
Simon
i am putting together the goods for my first amp build (greenhorn and then some) pcb and parts kit are ordered.
after a lot of digging i have a satisfactory quote from a uk supplier for the following:- Hammond 372JX, 2 x Hammond 1650 FA, EL84 sovtek matched quad, 5U4 GT, pair 12AT7 (ECC 81)
fit for purpose? please advise.
thanks
Simon
The transformers look fine, not sure about the rectifier tube, 5AR4/GZ34 is specified? Power tranny is a bit more than what you need but that is always a good thing, will run cool too.
I'm not sure if anyone has tried the Sovtek EL84's yet.
http://www.diyaudio.com/forums/tubelab/176888-favorite-outputs-simple-p-p.html
I'm not sure if anyone has tried the Sovtek EL84's yet.
http://www.diyaudio.com/forums/tubelab/176888-favorite-outputs-simple-p-p.html
This is supplier's reply that determined the choice of 5U4,
"With your power tranny you can have one 5U4 or you can run two 5R4.
With a 5v @ 4 amps heater winding this means you can have two 5R4 with a total handling of 500ma d.c.. The benefits speak for themselves.
Coz the 5U4 heater needs 5v/3amps you can only use one @ 300ma d.c.
you will need an extra Octal socket
If your rectifier tubes are PCB mounting you can probably only use one rectifier tube.
If it had to be a choice of one tube only , then the 5U4 has better specs on its own."
As this is a learning exercise for me i'm running hard to keep up but exercise is good for you is'n't ?
"With your power tranny you can have one 5U4 or you can run two 5R4.
With a 5v @ 4 amps heater winding this means you can have two 5R4 with a total handling of 500ma d.c.. The benefits speak for themselves.
Coz the 5U4 heater needs 5v/3amps you can only use one @ 300ma d.c.
you will need an extra Octal socket
If your rectifier tubes are PCB mounting you can probably only use one rectifier tube.
If it had to be a choice of one tube only , then the 5U4 has better specs on its own."
As this is a learning exercise for me i'm running hard to keep up but exercise is good for you is'n't ?
The Simple PP can only use one rectifier tube, so if you use a 5U4 you will need to change the first capacitor in the power supply from 47uF to 40uF or less, and the B+ voltage will then be lower than designed, by maybe 10 or 20 volts.
Since this is a first amp build, it's easiest (and best) to stick to Plan A, which is usually to follow all the designer's recommendations. Since Tubelab has supplied the PCB and all components for the PCB you can't go wrong there, and it would be a good idea to fit the specified rectifier too.
I would be inclined to hit up your supplier for a 5AR4/GZ34 and some JJ EL84 output tubes, otherwise just get the trannies and 12AT7's from your supplier, and buy the rectifier and output tubes elsewhere (like ebay USA).
It can be a stressful time ordering the parts, I know only too well...
Since this is a first amp build, it's easiest (and best) to stick to Plan A, which is usually to follow all the designer's recommendations. Since Tubelab has supplied the PCB and all components for the PCB you can't go wrong there, and it would be a good idea to fit the specified rectifier too.
I would be inclined to hit up your supplier for a 5AR4/GZ34 and some JJ EL84 output tubes, otherwise just get the trannies and 12AT7's from your supplier, and buy the rectifier and output tubes elsewhere (like ebay USA).
It can be a stressful time ordering the parts, I know only too well...
Thanks Ian,
I changed the order to include a 5AR4/GZ34 but left the Sovtek EL84's in if no-one has tried them then I can let you know how they go.
Guitars, Musical Instruments, and Musical Equipment from Guitar Center offer matched EL84's with the option of hard,medium or soft what's that about? good prices too.
Simon
I changed the order to include a 5AR4/GZ34 but left the Sovtek EL84's in if no-one has tried them then I can let you know how they go.
Guitars, Musical Instruments, and Musical Equipment from Guitar Center offer matched EL84's with the option of hard,medium or soft what's that about? good prices too.
Simon
Not sure, something to do with gain I would guess. I would go with medium or ask them what's best for a hifi amp.
I am not familiar with the Guitar Center's grading criteria but Groove Tubes rates the distortion characteristics of their power tubes on a 1 to 10 scale. This makes a difference on a guitar amp that is normally operated in clipping.
It should not make too much difference on a HiFi amp. I got a bunch of used Groove Tube 6L6GC's and found that I could squeeze a little more power out of #1's (soft) than #10's (hard). It didn't make a real big difference in sound in a HiFi amp, but I liked the 10's in a Bandmaster cranked to 10.
yeah- none of us ever run our tube hi-fi amps into clipping
I said none of us ever run - oh forget it
George - I's luvin the Simple PP in pentode with 6P14Ps and NOS 12AT7 - photos to follow
Several folks have said the same about the JJ's - I might add some to my next parts order (rebuild of EL34 P/P amp underway) .
George, et al - I'll ask here as I can't remember seeing it mentioned elsewhere - out of curiosity, what do you like to run the bias at on the JJ's? I'll sheepishly note that I never measured the amp before it went to Daniel for testing, and since it came back on Sunday, it's just been making music.
I have left the 270 ohm cathode resistors in my amp for most conventional use. This seems to be the best compromise. It may result is a faint red plate on some tubes and the JJ's could be pushed a little harder but there isn't much to gain.
The JJ's (and a very few others) can be operated with considerably higher plate voltages for power output levels up to 30 WPC. This involves some serious modifications to the design.
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