Thank you George and Those Who Helped Me
I finally got my pc board in Hammond chassis, hooked to Klipsch speakers. Sounds fantastic!
First try had one speaker out. Ground. Try again. The other speaker. Connection to opt was loose.
Now it's in music cabinet, tubes glow so o o nicely. And sounds great.
Enjoying an 18 year old. Scotch.
Thank you George and those who helped me. That would be those who posted to my posts, and those who have posted on the site before.
Here's to you.🙂
I finally got my pc board in Hammond chassis, hooked to Klipsch speakers. Sounds fantastic!
First try had one speaker out. Ground. Try again. The other speaker. Connection to opt was loose.
Now it's in music cabinet, tubes glow so o o nicely. And sounds great.
Enjoying an 18 year old. Scotch.
Thank you George and those who helped me. That would be those who posted to my posts, and those who have posted on the site before.
Here's to you.🙂
Wohoah!! Cool to see the guys gave you a big hand in completing a working Amp. Well done,
Enjoy!
Excellent!
Let me know your setup prior to the amp, I can give you some tips to get even better sound, especially if you're using a computer to stream to a DAC.
Enjoy the SET Tube Amp sound! 😀
Right now I am using a iPod for input. Have been using the amp for about a month. Didn't want to make any changes until the amp had been in use for a while.
Changes coming one by one are
a) input switch so I can use iPod, turn table with preamp, or CD player.
b)volume control, Alps
c)switches for triode/up, and another for cf
d)cathode resistor switch, to use current EL34s, and KT77s or KT88S.
I have some different 12at7 tubes. Started with a JAN-Phillips and Saturday switched to an RCA black plate.
I was surprised by change. The"invisible fullness" richness was gone, and now the music is much "clearer", audio like putting your glasses on. Sharper, more distinct.
Also have Mullard and Telefunken 12at7s to try.
Changes coming one by one are
a) input switch so I can use iPod, turn table with preamp, or CD player.
b)volume control, Alps
c)switches for triode/up, and another for cf
d)cathode resistor switch, to use current EL34s, and KT77s or KT88S.
I have some different 12at7 tubes. Started with a JAN-Phillips and Saturday switched to an RCA black plate.
I was surprised by change. The"invisible fullness" richness was gone, and now the music is much "clearer", audio like putting your glasses on. Sharper, more distinct.
Also have Mullard and Telefunken 12at7s to try.
I use an external switch box - 4 inputs, 1 out - to change music sources. With several amps that I take turns using, this makes it easier to change them... fewer cables to mess with.
I've used 6l6GC; EL-34; KT-88's with a 560 ohm cathode resistor... no problems.
If you can find a Sylvania Gold Brand GB-6201 black plate, give it a try... it's my favorite 12AT7 tube.
I've used 6l6GC; EL-34; KT-88's with a 560 ohm cathode resistor... no problems.
If you can find a Sylvania Gold Brand GB-6201 black plate, give it a try... it's my favorite 12AT7 tube.
You use the KT88s with the 560 resistors?
I was under the impression they needed a higher diss.
I was under the impression they needed a higher diss.
I've used both EH and Gold Lion KT-88 with a 560 ohm resistor, not a problem for several years now...
I also have EH and Gold Lion KT88 and most of the time I also use a 560 ohm cathode resistor which works well for me.
I consider the EH KT88 a bargain especially if you can get them at discounted prices. I got the Gold Lions when Parts Connection
was offering them at 33% off, even with that discount they were still expensive at $80 a pair.
I also use 560 for KT88's most of the time. If I flip the correct switch, I can take it down to around 480, but can't say I've heard much difference. For EL34's I use more like 840 ohm.
Just been reading a few web pages on Tubes and schematics and found people saying they prefer the KT-88 to the 300B in SET configuration.
I really like my KT-88 by Electro-Harmonix in my Tubelab SSE. I don't feel like I am missing out on anything.
Once I got the amp working, I had to do much more work to isolate my DAC from USB power noise. It was well worth it.
These days I am getting obsessed (what's new) in making Tube preamps. I'd use them in several places, music playback in just one of them. I do think about having them in lieu of my electronic instruments.
I see that George has been working on his Analogue Synth rig, including semi-modulars and modulars.
I've built my own Analogue Modular in the meantime too, doing practically 90% of it all myself:
- PCBs,
- faceplates/metal-work,
- faceplate label and design,
- casing wood-work and metal-work,
- Very low-noise Dual-Rail Linear Regulated PSU
- Power Distribution
Of all this, I am not too big on doing the metal work and the drilling of the PCBs - they're all home-etched except one, which is a PCB of the Thomas Henry VCO-555 that I bought from Fonik.
I have also improved my Soundcraft Delta mixer's signal path, and done a fair amount of similar work on my Roland JX-3P which now sounds much better.
I briefly tested the unbalanced Tubed sound of an ART Tube MP between my Kurzweil K2500XS+KDFX and the Soundcraft. It sounded quite cool for drums and brass/pads especially.
On the other hand, this is a starved plate design and it's supposedly hard to make that sound good.
Now imagine that in all our Poly Analogues, we had that Mixer + Amp stage with Tubes instead of SS... That's what is bugging me.
In the meantime I also did a lot of work to further the quality of Linear Regulated PSUs during lockdown.
I see people recommending choosing the speakers for their system first and then choosing the amp type.
I must be living in another dimension, because the SET Tube amplifier topology is a huge revelation that I want everything to revolve around. That means, choosing SET first and foremost, AND THEN, choosing efficient speakers to go with them (or even try the Full-Range pairings that some found to be even better down the line).
To me, there's nothing better than high-rate DSD (DSD256 and above) through a well-isolated, well-powered, well-clocked native DSD DAC into a well-designed SET Tube amp.
So thanks again, George and the many cool folks who helped me get it running along the way.
I really like my KT-88 by Electro-Harmonix in my Tubelab SSE. I don't feel like I am missing out on anything.
Once I got the amp working, I had to do much more work to isolate my DAC from USB power noise. It was well worth it.
These days I am getting obsessed (what's new) in making Tube preamps. I'd use them in several places, music playback in just one of them. I do think about having them in lieu of my electronic instruments.
I see that George has been working on his Analogue Synth rig, including semi-modulars and modulars.
I've built my own Analogue Modular in the meantime too, doing practically 90% of it all myself:
- PCBs,
- faceplates/metal-work,
- faceplate label and design,
- casing wood-work and metal-work,
- Very low-noise Dual-Rail Linear Regulated PSU
- Power Distribution
Of all this, I am not too big on doing the metal work and the drilling of the PCBs - they're all home-etched except one, which is a PCB of the Thomas Henry VCO-555 that I bought from Fonik.
I have also improved my Soundcraft Delta mixer's signal path, and done a fair amount of similar work on my Roland JX-3P which now sounds much better.
I briefly tested the unbalanced Tubed sound of an ART Tube MP between my Kurzweil K2500XS+KDFX and the Soundcraft. It sounded quite cool for drums and brass/pads especially.
On the other hand, this is a starved plate design and it's supposedly hard to make that sound good.
Now imagine that in all our Poly Analogues, we had that Mixer + Amp stage with Tubes instead of SS... That's what is bugging me.
In the meantime I also did a lot of work to further the quality of Linear Regulated PSUs during lockdown.
I see people recommending choosing the speakers for their system first and then choosing the amp type.
I must be living in another dimension, because the SET Tube amplifier topology is a huge revelation that I want everything to revolve around. That means, choosing SET first and foremost, AND THEN, choosing efficient speakers to go with them (or even try the Full-Range pairings that some found to be even better down the line).
To me, there's nothing better than high-rate DSD (DSD256 and above) through a well-isolated, well-powered, well-clocked native DSD DAC into a well-designed SET Tube amp.
So thanks again, George and the many cool folks who helped me get it running along the way.
Same dimension I am living in. In my own short DIY journey after a few amp and speaker projects I wanted to try both a very well measuring SS amp and a subjectively very good sounding tube amp (Tubelab SSE). After building and listening to both for an extended period of time in the same room with the same speakers it's the SSE that is staying and dictating what comes next. Funny thing is I am far outside the listening profile many posts point to as being well suited to SET amps and full range speakers. My problem now is I want a tube amp in every listening space.
Our situations are even more alike than you thought:
My Totem Mites aren't supposed to cut it either regarding the efficiency ratings and they sure aren't made of a single full-range each, being small bookshelves with 2-way on each side.
However they sound really good.
And here's the kicker:
You don't necessarily need very high efficiency in a small room.
This said, I still would like to build an efficient, open-baffle with a single full-range to try it with that particular SET.
Here's an anecdote about the common recommendation of choosing speakers before anything else.
Someone on YT said that (of course, he wants either SS or PP Tube because he chooses the speakers first).
Later in the same video, he mentions that when he put his SET Tube in again, he found out that a lot of music he couldn't listen to properly - like some of Bowie's music - he could now listen to and enjoy.
So his recommendation was to choose SPEAKERS FIRST, because SET 'limited the set of speakers he could choose from'...
...but in so doing, he removed SET from the equation altogether and found out he was limiting his music to listen to... 😱
...and somehow this is acceptable to him?
Only makes sense if you're living in La-La Land.
Other than that, the bloke is cool, no doubt.
(That's Kevin Deal from Upscale Audio, making no sense whatsoever in his choices and recommendations but he hasn't noticed at all...)
"These are the best inefficient speakers! You're not limited by SET! But THERE'S A WHOLE LOT OF GREAT TRACKS YOU CANNOT ENJOY ANYMORE!"
Does this make sense at all? In his mind it does somehow...
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Mind you, anywhere I've seen people answer the question 'what component should I choose first' in forums and so on, the common one is to start with speakers.
I am a total contrarian in this, and actually I'd like SET Tube in surround for movies as well (and surround tracks).
I am a total contrarian in this, and actually I'd like SET Tube in surround for movies as well (and surround tracks).
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Managed to do some low-voltage experiments with the salvaged sockets and 12AX7 from my Behringer Tube Composer - soldered leads to the sockets so that I can easily plug one half or the two triodes of a single bottle to the breadboard.
It's quite interesting how low-voltages make distortions very apparent. As a side benefit, it seems quite easy to make a low-voltage Guitar Tube amp, of the colouring variety! Now that isn't what I was planning to do, but now it opens up quite cool avenues that I can use with my Peavey Raptor EXP if I choose to go this route at one point!
Add a small Spring Reverb, internalise some simple tone control, maybe add a couple of extra Distortion flavours (e.g. Diodes in between two Tube stages) a Woofer and a purpose-built cabinet and we'll be ROCKING!
This little test-setup I have on less than half of our dinner table is nice: it allows me to test topologies without breaking anything. I have a simple breadboarded Linear Reg 12V for the plate resistors, and a separate Linear 6V DC wall-wart for the heaters. I made a small Input and Output RCA module from a 4-RCA unit salvaged from what could be an old VHS player, with the HV Caps already soldered to it and the outputs on leads that plug into the breadboard. The breadboard allows me to try out things like using a Cap on the Cathode Resistor or not, less conventional configurations, even tested output from the Cathode instead of the plate, unconventional biasing, etc...
A lot of fun for starting with tubes, I can tell you. 😛
OK, for final implementation, we'll definitely need Higher Voltage (most probably 150+V and by that time I might switch to some other tubes as well), I'll need different parts, some of which I may not have here, like those high-power plate resistors. I mean I may have one for two close enough salvaged for a single channel to experiment with, but for a final build, I want to match components, so I'll need a lot more from a single batch if at all possible.
Actually, the matching applies to all components across the channels, and that's a lot of work.
This can wait, as I still need to experiment with alternate topologies and I can do some of that (with distortion apparent) with my low-voltage mini-Lab. 😛
It's quite interesting how low-voltages make distortions very apparent. As a side benefit, it seems quite easy to make a low-voltage Guitar Tube amp, of the colouring variety! Now that isn't what I was planning to do, but now it opens up quite cool avenues that I can use with my Peavey Raptor EXP if I choose to go this route at one point!
Add a small Spring Reverb, internalise some simple tone control, maybe add a couple of extra Distortion flavours (e.g. Diodes in between two Tube stages) a Woofer and a purpose-built cabinet and we'll be ROCKING!
This little test-setup I have on less than half of our dinner table is nice: it allows me to test topologies without breaking anything. I have a simple breadboarded Linear Reg 12V for the plate resistors, and a separate Linear 6V DC wall-wart for the heaters. I made a small Input and Output RCA module from a 4-RCA unit salvaged from what could be an old VHS player, with the HV Caps already soldered to it and the outputs on leads that plug into the breadboard. The breadboard allows me to try out things like using a Cap on the Cathode Resistor or not, less conventional configurations, even tested output from the Cathode instead of the plate, unconventional biasing, etc...
A lot of fun for starting with tubes, I can tell you. 😛
OK, for final implementation, we'll definitely need Higher Voltage (most probably 150+V and by that time I might switch to some other tubes as well), I'll need different parts, some of which I may not have here, like those high-power plate resistors. I mean I may have one for two close enough salvaged for a single channel to experiment with, but for a final build, I want to match components, so I'll need a lot more from a single batch if at all possible.
Actually, the matching applies to all components across the channels, and that's a lot of work.
This can wait, as I still need to experiment with alternate topologies and I can do some of that (with distortion apparent) with my low-voltage mini-Lab. 😛
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Pretty much settled on the design of a high-voltage version of a tube preamp stage. Yet untested though.
In parallel, this holiday period, I noticed a few things after the SSE stopped working one day:
PCB has been heating up around the main PSU resistor as I must have soldered it too close to the board. This caused a connection to one filtering cap to become intermittent or fail altogether. The fault can be diagnosed with the DVM in resistance measuring mode.
The fix is easy but this is a good opportunity to improve my build.
In another post, George mentions the diodes and the CL140 to protect the Tube Rectifier but in my SSE, I was told to just bridge them and that's how they've been all this time.
The advice to bridge them at the time makes total sense though, as I was doing my first build, hit a snag and we needed to find a stable, working amp with the help of the good folks here and George himself. The issue turned out to be a faulty RCA I had salvaged thinking I was going to win something here and instead I ended up being puzzled for a long time about why one channel was not working at one point.
I don't think the missing components here caused any trouble for my Russian Sovtek 5AR4 but if adding them can improve its operating life, these are worthy additions. Need a dive in the parts stock to check whether I have all these components.
First though, I'll clean up the pads and are around the high-Wattage resistor, remove it, re-test it, and solder it back but with a good clearance between it and the board.
Touching up socket solder joints would be a good thing as well.
And finally, right after this these holidays will bring a choke and a motor run cap to the SSE.
Still no volume pot and still only SE mode.
The volume nowadays is either controlled from the audiophile software player (Audirvana in my case) or from the physical pot in the external DAC.
I gave a solid-state Phono stage to my gf, but there's no Volume pot there.
Instead of hacking it and adding a stereo pot to it, I am planning to instead use my DIY Tube Preamp with the Phono stage and add volume control there.
I finally found a spare 12AU7 in addition to the two 12AX7s from the Behringer gear. I'd need a socket for it but it could be a worthy inclusion to the Tube Preamp.
Things are looking up.
In parallel, this holiday period, I noticed a few things after the SSE stopped working one day:
PCB has been heating up around the main PSU resistor as I must have soldered it too close to the board. This caused a connection to one filtering cap to become intermittent or fail altogether. The fault can be diagnosed with the DVM in resistance measuring mode.
The fix is easy but this is a good opportunity to improve my build.
In another post, George mentions the diodes and the CL140 to protect the Tube Rectifier but in my SSE, I was told to just bridge them and that's how they've been all this time.
The advice to bridge them at the time makes total sense though, as I was doing my first build, hit a snag and we needed to find a stable, working amp with the help of the good folks here and George himself. The issue turned out to be a faulty RCA I had salvaged thinking I was going to win something here and instead I ended up being puzzled for a long time about why one channel was not working at one point.
I don't think the missing components here caused any trouble for my Russian Sovtek 5AR4 but if adding them can improve its operating life, these are worthy additions. Need a dive in the parts stock to check whether I have all these components.
First though, I'll clean up the pads and are around the high-Wattage resistor, remove it, re-test it, and solder it back but with a good clearance between it and the board.
Touching up socket solder joints would be a good thing as well.
And finally, right after this these holidays will bring a choke and a motor run cap to the SSE.
Still no volume pot and still only SE mode.
The volume nowadays is either controlled from the audiophile software player (Audirvana in my case) or from the physical pot in the external DAC.
I gave a solid-state Phono stage to my gf, but there's no Volume pot there.
Instead of hacking it and adding a stereo pot to it, I am planning to instead use my DIY Tube Preamp with the Phono stage and add volume control there.
I finally found a spare 12AU7 in addition to the two 12AX7s from the Behringer gear. I'd need a socket for it but it could be a worthy inclusion to the Tube Preamp.
Things are looking up.
Where to do stereo-to-mono?
Plans for the single full-range speaker driver with the SET nearly came to fruition as a couple of really old speaker towers appeared on the pavement this summer.
These old bugger sounded really good, very musical, quite in line with the Totem Mite sound.
Problem: one driver was buzzy... and I soon found out that with the glued on front panel, these drivers were a chore to remove.
Tried to fix the buzzy driver but couldn't. In fact, I couldn't even diagnose it properly but it seemed like if I touched part of the cone it helped with the buzzing somewhat.
So now I have kept the working full-range driver, and also kept one of the panels where it was mounted, threw away the cabinets, which means I already have the basis for a single full-range open baffle build.
Thus, I also need to operate a stereo-to-mono converter. This is easy and the question therefore becomes 'where do I put this?'.
Since Volume Control is techncially at the preamp level, it makes sense to also do it there and then to output the musical mono signal to the SET Tube Amp.
And hence, we have one more module to add to our DIY Tube Preamp build.
Plans for the single full-range speaker driver with the SET nearly came to fruition as a couple of really old speaker towers appeared on the pavement this summer.
These old bugger sounded really good, very musical, quite in line with the Totem Mite sound.
Problem: one driver was buzzy... and I soon found out that with the glued on front panel, these drivers were a chore to remove.
Tried to fix the buzzy driver but couldn't. In fact, I couldn't even diagnose it properly but it seemed like if I touched part of the cone it helped with the buzzing somewhat.
So now I have kept the working full-range driver, and also kept one of the panels where it was mounted, threw away the cabinets, which means I already have the basis for a single full-range open baffle build.
Thus, I also need to operate a stereo-to-mono converter. This is easy and the question therefore becomes 'where do I put this?'.
Since Volume Control is techncially at the preamp level, it makes sense to also do it there and then to output the musical mono signal to the SET Tube Amp.
And hence, we have one more module to add to our DIY Tube Preamp build.
Sheet Metal Punch Hole Punch. bought mine on ebay. just tighten with an allen wrench.
Gives a nice smooth hole.
Gives a nice smooth hole.
Hi Steve, you must be referring to one of the first posts. Indeed, and now I have a set of hole punches. I haven't used them yet, but I may need to revisit and re-work the holes more cleanly.
I think I am covered with the wrench. I have a T-shaped handle one with several exchangeable bits of various sizes.
The SET is under re-work. I removed the main large resistor as the contact was intermittent.
Cleaned it up, measured it - it measured well. Tinned the leads, added solder to the pads where some PCB browning occurred, re-soldered it with better clearance from the PCB underneath.
However, on re-mounting the PCB underneath the chassis, I may have remove that clearance again, so I now need to use longer spacers.
This will allow the resistor to keep its clearance above the board. Secondly, this will make the tubes go down further below the chassis. Some of the smaller tubes may be less visible, but simultaneously, the KT-88 bases, which are at quite a high potential, will then go below the chassis top which is a good thing.
Did some experiments and resistor tweaking with a low voltage tube/hybrid preamp or headphone stage during the past few days and nights.
Distortion was too much already with the iPhone's volume at around 70%. however, last night after a few more tweaks and tests, I managed to get fairly good subjective results, even at higher volumes. A pot allows tweaking the Plate load. I couldn't test with the Fostex SS bi-amped monitor at high volume last night, but this morning I did. It sounds quite good.
I tested with a 12AX7 (v. good) and a 12AT7 (not so good).
I also took the opportunity last night to gather some parts and transformers for a high voltage Tube Preamp section. Looking forward to it being used after a CD player's DAC out or a USB DAC out.
Distortion was too much already with the iPhone's volume at around 70%. however, last night after a few more tweaks and tests, I managed to get fairly good subjective results, even at higher volumes. A pot allows tweaking the Plate load. I couldn't test with the Fostex SS bi-amped monitor at high volume last night, but this morning I did. It sounds quite good.
I tested with a 12AX7 (v. good) and a 12AT7 (not so good).
I also took the opportunity last night to gather some parts and transformers for a high voltage Tube Preamp section. Looking forward to it being used after a CD player's DAC out or a USB DAC out.