Blue is B+ you can take it from anywhere after the power supply usually at or shortly after the third cap C3 22uf 450V. You can connect the blue to pin4 OR + terminal on C3.
Red connects to pin3 (signal out for output tube)
Output wires
Black is 0 (Neutral) - be sure you get both connected together and run a wire (black) back to your star ground point (bolt on the transformer).
For the output transformer color codes - I'll have to check when I get home, I don't remember which color is which.
Here's a way to tell....
Measure ohms reading from Black to yellow and black to green. The reading with the lowest resistance to common will be your 4 Ohm tap.
Hope that helps.
Cheers,
Bob
Hi guys, was wondering if anyone else has tried the diode mod Bobrown has suggested.
With further reading on other posts on the subject, i got the impression, at least with the 5y3 tube that this becomes a solid state rectifier and the tube itself becomes redundant.
Can anyone clarify this for me that i understood this right (Bobrown if your out there, any thoughts on the subject).
If so, i don't see the point in buying a new rectifier tube just yet if i try this mod.
In the meantime i have some russian 6p3s tubes and a tocos volume pot i have read good things about on there way, so hopefully can let you all know of any improvements these might add.
Scratch
With further reading on other posts on the subject, i got the impression, at least with the 5y3 tube that this becomes a solid state rectifier and the tube itself becomes redundant.
Can anyone clarify this for me that i understood this right (Bobrown if your out there, any thoughts on the subject).
If so, i don't see the point in buying a new rectifier tube just yet if i try this mod.
In the meantime i have some russian 6p3s tubes and a tocos volume pot i have read good things about on there way, so hopefully can let you all know of any improvements these might add.
Scratch
Just finished my 6p3p and will post some pics and building notes later. This can be a very good first diy tube amp if you study the schematic and wiring diagrams. The stock amp looks awesome, is quiet, sounds good, and with a few simple mods (rectifier diodes, new power tubes, and feedback resistors) is plenty loud enough and sounds great!
Paul
Paul
Wire both primaries in parallel or you may fry the transformer. The primary windings are sized based on the primary current when the windings are wired in series for 220-240V operation, when operating on 120V the current consumption will be twice that at 240V which could result in excessive heating in a single primary, the winding current is correct when both are wired in parallel..
So, I will put the two red wires together and wire them to one side of the wall AC current, and put the two black wires together and run them to the other side of the AC inlet.
Thank you Kevin!
Paul
Diode mod is there to protect transformer in the case of arc over in the rectifier tube, primarily a safety feature. Does not make the rectifier tube redundant. You keep all the properties of the rectifier tube (slow start & resistance & voltage drop) these all make a difference in performance of the power supply & subsequent circuits.
Arc over in rectifier tube = toasted transformer for this amp, add diodes no more worries.
Of course there are many ways to tame that cat. Some rectifiers are getting pricey so you can protect the rectifier tube and the power transformer with this simple $.24 mod.
Cheers,
Bob
Bad expierence with tube seller
Hi there , I have had a bad expierence with a Russian tube seller :ruTube.com I ordered some capacitors and tubes payed trough paypal and started to wait after 3 weeks I cancelled and this guy ( Nikolay ) sended me an Email explaining that there were holidays in Russia , so he convinced me I opened the acount and since then nothing he does not aswer my Emails . If you guys have some good experience post the names . With regards Paul
Hi there , I have had a bad expierence with a Russian tube seller :ruTube.com I ordered some capacitors and tubes payed trough paypal and started to wait after 3 weeks I cancelled and this guy ( Nikolay ) sended me an Email explaining that there were holidays in Russia , so he convinced me I opened the acount and since then nothing he does not aswer my Emails . If you guys have some good experience post the names . With regards Paul
Hi all, I am a new member, come from VietNam. Pls advise where to purchase all component for DYI above tube amplifier. Thanks for your help.
Huy- therains46@gmail.com
So my 6P3P kit arrived this week and when I opened it I found that a majority of the parts were damaged to some extent during shipping. When you pay $120 for shipping you'd expect some type of guarantee on the kit but this is not really the case. Siliconray offered to replace a transformer but I'd have to pay another $35 in shipping fees. Does anyone have a recommendation for someplace preferably in the US that I could buy a better transformer affordably?
Need to replace a: 3.5k to 8Ohm and 4Ohm OP transformer
Need to replace a: 3.5k to 8Ohm and 4Ohm OP transformer
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Edcor GXSE series go for the 10 watt version as they are very close in size to those (and sound better). You could use the 2.5K or the 5K either will work with those output tubes, but the 5K version should be a better match. These OT sound pretty good for the price. Downside is you order and have to wait for them to be built for you.. just what you wanted to hear after waiting for a banged up kit, but it will be worth the wait. Those bent bell ends can probably be fixed but they are not bolted on so you have to bend the tabs to get the bell ends off to bend them back. I'd order the Edcors above and bend the tabs on the ones you have good enough to get then installed and running then swap out when you get the edcors. Test the OTs first to be sure there's not shorts tho before putting B+ to them. If you dont want to test them be ready to unplug power - if there's a short it will start to smoke pretty quick. Likely they're ok just look like crap. I'd build the amp and replace the OTs with the Edcors and you'll have a decent sounding amp there. The Edcor OTs may night line up with the holes already punched in the chassis but you should be able to drill a few holes to get them to fit. Check the sizes of the Edcor to what you have in hand they should be close enough to get them to work. I've used the GXSE OT's (listening to them now) and they are very good, specially for the $$.
Link: EDCOR - GXSE10-8-5K
Cheers,
Bob
Might be a good idea to check the vdc on your powerlines.
Here in new eu-rope they kick all old 220vdc transformer audio out by having 231 to 237 vdc on the powerlines.
In the morning I measure 231 and later in the day goes up to 236-237vdc.
In trying to investigate came to know that big companies have the Eu-Brussels to raise the vdc so people hot up their audio, older machinery a.s.o. too much so destroying it. (.. really hate the eu..it kills a lot..)
Siliconray can provide a 240vdc transformer as well.
Here in new eu-rope they kick all old 220vdc transformer audio out by having 231 to 237 vdc on the powerlines.
In the morning I measure 231 and later in the day goes up to 236-237vdc.
In trying to investigate came to know that big companies have the Eu-Brussels to raise the vdc so people hot up their audio, older machinery a.s.o. too much so destroying it. (.. really hate the eu..it kills a lot..)
Siliconray can provide a 240vdc transformer as well.
If an older tube amp or others on 220vdc you can use a bucking trafo.
Take a 15 or ...vdc trafo f.e. (printer ..scanner.. phone ...loader ..a.s.o..) peel off the black cover and connect in phase opposition in series with the 220vdc
That extra transformer: its primary to the mains and secondary in anti-phase with the primary of the transformer to tube amp
Take a 15 or ...vdc trafo f.e. (printer ..scanner.. phone ...loader ..a.s.o..) peel off the black cover and connect in phase opposition in series with the 220vdc
That extra transformer: its primary to the mains and secondary in anti-phase with the primary of the transformer to tube amp
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