Congrats!!!!
Occam's razor strikes again...
We have all been there, and I hope you learned something along the way!
Next up...a P2P wired push pull !!! LOL
Occam's razor strikes again...
We have all been there, and I hope you learned something along the way!
Next up...a P2P wired push pull !!! LOL
Yesterday:
1. Matched Electro-Harmonix KT-88
2. Sovtek 5AR4
3. Generic 12AT7 from China (can't tell which brand if any)
Today, I replaced the 12AT7 for the original 12AT7EH, and it is still working too!
Therefore, this makes it:
1. Matched Electro-Harmonix KT-88
2. Sovtek 5AR4
3. Electro-Harmonix 12AT7EH
All Russian tubes.
Thanks 🙂 Yep, learned a lot, thank you.
P2P-wired push pull, why not? 😀
Actually, what I would like to do is two mono-blocks or a quad-mono SET (this will be for surround and multi-amping in all-tube configuration), so let me know if there's something cool to build.
In the meantime, my workshop area is finally liberated from the imposing amp. You may have noticed how mine isn't a cramped layout, but a rather airy one, in that there is ample space for the big Edcors, distance from the OPT to the Power one, and distance from the Power one to the tubes themselves. The actual dimensions are inspired by the two Conrad-Johnson pre-amp + amp I saw at an audiophile friend's place. So my amp is big and left not much for anything else on the table.
So now, there is a set of other DIY projects that can come to fruition, all the while listening to the SSE!
I have a few linear power supplies to build and my AC Filter box to finish.
Yesterday, we realised that we'll need a separate Phono pre-amp for my gf's vinyl playback (a Technics SL-1800 Direct-Drive that I have a list of 18 mods I want to perform on 😛 )
So I am also looking for a good Tube Phono pre-amp. I have also seen people get great results with SS Phono pre-amps coupled with tube amps, so that could be interesting too.
All in all, a fuller pre-amp build with switchable inputs and one with a set of RIAA Curves could be interesting.
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I went here next... PS-4 & PS-5 Tube Power Supplies
I used the PS4 supply but p2p wired the EL84 push pull which you could easily make monoblocks if you wanted to spend the money.
Its a nice little amp with good bass.
I implemented George's CCS on the front end and used red LEDs for bias on the font end stage.
I also implemented a CCS on the power stage fixing it at like 80mA (40mA per tube) if i remember correctly.
A fun project to play around with and learn.
I found my thread on it...
http://www.diyaudio.com/forums/tubes-valves/171386-anyone-ever-made-el84-p-p-circuit-referenced-tubecad-journal-site.html
I used the PS4 supply but p2p wired the EL84 push pull which you could easily make monoblocks if you wanted to spend the money.
Its a nice little amp with good bass.
I implemented George's CCS on the front end and used red LEDs for bias on the font end stage.
I also implemented a CCS on the power stage fixing it at like 80mA (40mA per tube) if i remember correctly.
A fun project to play around with and learn.
I found my thread on it...
http://www.diyaudio.com/forums/tubes-valves/171386-anyone-ever-made-el84-p-p-circuit-referenced-tubecad-journal-site.html
Thanks.
Another thing we realised yesterday: since we're going to use the Totem Mites with the tube amp for a while, we now have no other front speakers with the SS amp, which means that for multi-channel, we need two more speakers (we were re-using the Mites for Stereo and for Surround audio and Surround for movies as well).
Now, my longer-term goal in building a SET Tube amp is to pair it with either a Full-Range DIY speaker or a multi-way incorporating a FR and a Ribbon Tweeter.
So I am looking for that and I may start an open-baffle build actually.
For this, I will have to research the FR + Ribbon Tweeter pairing.
Another thing we realised yesterday: since we're going to use the Totem Mites with the tube amp for a while, we now have no other front speakers with the SS amp, which means that for multi-channel, we need two more speakers (we were re-using the Mites for Stereo and for Surround audio and Surround for movies as well).
Now, my longer-term goal in building a SET Tube amp is to pair it with either a Full-Range DIY speaker or a multi-way incorporating a FR and a Ribbon Tweeter.
So I am looking for that and I may start an open-baffle build actually.
For this, I will have to research the FR + Ribbon Tweeter pairing.
I am very fond of nice full rangers. I have built a few of the planet 10 "fonkens". Currently my fronts are the fonken floor standers mkII. They put out incredible bass for a 4" full range - sometimes dont even need to crank up the sub...unless the wife is not home...LOL
Currently for us, the Totem Mites are on DIY Stands.
I am inclined to try an open-baffle setup as I already have a few boxed implementations.
They will also make it easier to try in the multi-amped configuration as well as the access to the crossover is immediate.
I am inclined to try an open-baffle setup as I already have a few boxed implementations.
They will also make it easier to try in the multi-amped configuration as well as the access to the crossover is immediate.
I found somewhere your post on the Aikido build or rebuild - quite interesting.
I am learning about Phono stages, pre-amp circuits and RIAA implementations. Quite interesting.
I have built a couple tube phono stages and i have to say none of them sound as good as my old Yamaha CA810 phono stage.
I love my aikido preamp though....
I love my aikido preamp though....
Yup an integrated amp from the 70s...many from that Era have rock solid phono stages...and you can fix them when they break!
Natural Sound Stereo Amplifier CA-810 Ampl/Mixer Yamaha Co.;
Natural Sound Stereo Amplifier CA-810 Ampl/Mixer Yamaha Co.;
Pal of mine in college had a CA-810.
I still have my CT-610 and CA-610 in my warehouse of junk.
Win W5JAG
I still have my CT-610 and CA-610 in my warehouse of junk.
Win W5JAG
That mid-to-end of 70's and part of the 80's had a great set of equipment from Japan. I remember, as a kid and teen that my uncles were raving about Sansui, Yamaha, Pioneer, Aiwa, Sony, Sanyo, TEAC and Kenwood.
Troubling issue with the KT-88 base.
I saw something very odd and worrying today:
If I measure with the DMM from Ground to the KT-88 base which is made of metal, I get something like 90VDC
The amp works, but this seems like it shouldn't happen as the metal base is exposed in the way I built it.
Either it's normal, in which case, I should rebuilt so that the metal isn't exposed, or it's totally not normal at all, making my amp quite hazardous to health. In that case what should I do?
I saw something very odd and worrying today:
If I measure with the DMM from Ground to the KT-88 base which is made of metal, I get something like 90VDC
The amp works, but this seems like it shouldn't happen as the metal base is exposed in the way I built it.
Either it's normal, in which case, I should rebuilt so that the metal isn't exposed, or it's totally not normal at all, making my amp quite hazardous to health. In that case what should I do?
my guess is that it has something to do with the heater wiring. The heater voltage is "elevated" from ground reference of 0 to B+/4 roughly which in your case would be about 90V.
Not sure there is anything you can or should do about it other than non metallic base tubes.
I run new issue Tung Sol 6550's in the SSE and they really rock. More than the KT88s and the EH KT90's i have.
I am running pretty high voltage ~480 and bias the power tubes to about 80 - 90 mA....typically.
Not sure there is anything you can or should do about it other than non metallic base tubes.
I run new issue Tung Sol 6550's in the SSE and they really rock. More than the KT88s and the EH KT90's i have.
I am running pretty high voltage ~480 and bias the power tubes to about 80 - 90 mA....typically.
i looked a little and some folks say that the pin 1 on the KT88 "sometimes" is connected to the metal base.
you would have to see why you have that voltage on pin 1 of the PCB otherwise it is some internal tube connection.
you would have to see why you have that voltage on pin 1 of the PCB otherwise it is some internal tube connection.
It sure looks like the first possibility, I found the folllowing on another forum for another amp:
So I guess that one way to protect against this is to put a cage all around the amp as some manufacturers do.
Another design modification I thought about was to use longer standoffs so that the PCB is further down with respect to the chassis. This will require that I widen the holes, especially for the KT-88s as the base is quite wide.
This will have the effect of making the smaller tubes less visible, but I can live with that.
It will also make the bases within the chassis instead of above it, and I believe I have seen somewhere that this is a good thing for SQ.
I am not sure there's a possibility of insulating the base.
I am not sure either of how to 'move tie point away from pin 1' and if that is technically possible at all with the SSE.
On our own forum I found the following:
Is it possible to do this within the SSE with its PCB/schematics?
Is there any downside?
Is it possible to do this within the SSE with its PCB/schematics?
Is there any downside?
I've never measured the voltage on the metal base of tubes I have in my SSE. I find that after about 15 mins.
those bases get so hot that there is more danger of scorched fingers than from a low voltage jolt.
You can use some kind of cage if you're very concerned about the voltage.
those bases get so hot that there is more danger of scorched fingers than from a low voltage jolt.
You can use some kind of cage if you're very concerned about the voltage.