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Dual Mono Tube Mic Pre (pultec MB-1) separate a bag PSU's per channel. Odd, but #fun [emoji4]
electron tube vco based off of eric barbour/Metaonix's 2D21 VCO seen on Ken Stone's DIY Synth page.
I know I sound like a party pooper. I think you take on too big of a bite from looking at your schematic. At the very front end of your schematic, you have 3 transformer in parallel, each will drive the other, their impedance and output will interfere with each other.
As I said before, I want to just jump and build the ultimate build too. It dose not work that way. I made a mistake in the past in guitar amp that I thought I had 30 years experience in analog and RF electronics designs that this is child's play. That I should have no problem designing and building amps. I was wrong. Other than offending knowledgeable people, I ended up still putting in the time, prototyping the circuit and learn the stuffs.
Audiophile is a very special field, even with a lot of designing experience, there are still a lot to learn. I spent two months here asking question, studying everyday, still I gave up the idea of build the ultimate amp the first try. Mind you I already successfully built a few guitar amps successfully. This is just so different that I feel humbled and want to learn here.
If I were you, I'll break your design into a few small section, prototype them and get the most out of it. Then you put them together and hopefully it works out.
As I said before, I want to just jump and build the ultimate build too. It dose not work that way. I made a mistake in the past in guitar amp that I thought I had 30 years experience in analog and RF electronics designs that this is child's play. That I should have no problem designing and building amps. I was wrong. Other than offending knowledgeable people, I ended up still putting in the time, prototyping the circuit and learn the stuffs.
Audiophile is a very special field, even with a lot of designing experience, there are still a lot to learn. I spent two months here asking question, studying everyday, still I gave up the idea of build the ultimate amp the first try. Mind you I already successfully built a few guitar amps successfully. This is just so different that I feel humbled and want to learn here.
If I were you, I'll break your design into a few small section, prototype them and get the most out of it. Then you put them together and hopefully it works out.
....Alan, I'm glad u said this.... I have this issue w/ many things in my life, whether it is writing music, recording other musicians,producing beats & writing songs... It's all the same, so hearing that is a very huge stepping stone in my life, simply because I have this issues w/ Music.... And am aware of it.. but have never seen this same issue in electronics... Until now.
So taking your advice, I'll set aside "THEE EPIC" ...and just build whatever I can for now :")
I hope I can still receive help from your guys, as we just have seen here that Alan not just has helped me with my build here and the issues I face, but the issues I face on a daily basis with everything! :*}
...thanks guys:')
A very Thankful + Open,
-thee:]
Glad I can of help. I actually use a Fender Bassman 100 chassis for experiment. I actually build 3 different preamps into the chassis so I can play my guitar through them using switch box to compare. I build one preamp exactly the same as the famous Marshall JCM800 2204, I use it as the standard for A/B comparison. Then I start designing my own, compare, mod, compare, mod........... Then I build a Dumble as the third channel. It is very different from the Marshall but is very good too. So I keep working and comparing until I get my sound. Then I build all parts of the circuit into a brand new chassis all in one shot.
Knock on wood, I just designed two amps and both worked great and sounded great with a little tweak only. It will be too damaging to build the amp, then experiment, mod over and over. After a while, it becomes unreliable.
Experiment one stage at a time. Say use a known power amp, build your preamp section one at a time and test. Best if you have a ready made preamp as a standard for A/B comparison. Then work on the mixing 3 different signal sources. Then you work on the power amp.
Ask people here how they prototype their circuits and find one way you like. A lot of them just nail everything onto a piece of wood. I would put aluminum foil to cover the wood to serve as conductive chassis.
I would get some books to read through how they design, I am searching for a good book, I read through the one by Morgan Jones, I don't particularly like it even though some people like it. I still use RDH4 right now. But that is a more advanced book written in the old days, very dry!!! The more you read, the more you appreciate what you build. Take your time, read a lot of threads here, ask questions and have fun.
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Hey, I've got the same 'issue'.. It wasn't until my 30's when I finally got a proper level of focus.. But it was at the cost of energy.. (aging sucks).
I play just about every instrument there is, was in a few bands from Jazz to rock to techno. Have LED projects, robot projects, audio projects, car projects, computer projects, pets, garden, etc..
You mentioned the Ken Stone synth.. I've got big modular synth.
The tube synth is a project I've been working on for years.. Just have a bunch of bits of it in a box right now, though.
Being 'all over the place' definitely has its benefits, too.. I think in the past they called multi-skilled, focus lacking people 'renaissance men', but now they just say we're ADD.
Ha ha, I am one of those that is all over the place. I started electronics in 78 modding my Twin Reverb when I was still playing guitar. I made my power scaling by a variac on the power and PI section while keeping voltages on the preamp and filaments constant. Worked really great. I was so into electronics that I quit music all together in 79 and started my long career in engineering design electronics. Been a firmware engineer for a year or so, before changing to all hardware in early 80s and move into analog. Electronics has been my passion, I change fields by changing jobs. From working with Lecroy in ADC modules, to IC design with Exar, to ultrasound medical imaging with Seimen before I settle to designing mass spectrometers for 10 years. Then I got restless and move onto RF before I retired. I am all over the place.
Now that I retired, I go back in full circle and got back into guitar amps for two years designing two of them. Now I am here learning audiophile and trying to design a tube power amp. I already have plan to design a SS power amp next!!! Other than mass spectrometer electronics, I am expert in nothing but just know something in a lot of fields!!! That's how I enjoy my electronics. 30 years of career, my number one passion is still electronics.
Now that I retired, I go back in full circle and got back into guitar amps for two years designing two of them. Now I am here learning audiophile and trying to design a tube power amp. I already have plan to design a SS power amp next!!! Other than mass spectrometer electronics, I am expert in nothing but just know something in a lot of fields!!! That's how I enjoy my electronics. 30 years of career, my number one passion is still electronics.
Wanted to keep the thread going by uploading some pics of the transformers both Audio + Power. *Tried to make the pictures focused so u can read the diagrams on them.
.hope u like the gauges😉 I sure do:")
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
.hope u like the gauges😉 I sure do:")
does anybody know anything about any of the pictured transformers above^
I did a few Google's w/ little luck, i have some print-outs on a few of them, but its pulled from a catalog database for a store. The computer-catalog is large enough it has military parts in it's databases if that means anything). I'll post pics
I did a few Google's w/ little luck, i have some print-outs on a few of them, but its pulled from a catalog database for a store. The computer-catalog is large enough it has military parts in it's databases if that means anything). I'll post pics
Pictured transformer is for matching high inpedance line to 8ohm(or so) speaker. It used on long line(several hundred feet, such as cumpus PA) transmit audio power with high inpedance line. High inpedance means high voltage and low current, hence loss from line could minimized. Ther some standards, 50V-line, 70V-line, 100V-line. This transformer will adapt to 50V and 70V line.
This may helpful.
Constant-voltage speaker system - Wikipedia, the free encyclopedia
This may helpful.
Constant-voltage speaker system - Wikipedia, the free encyclopedia
More than likely they are intended for aircraft and shipboard intercom and PA systems. The frequency response of those systems was tailored for speech intelligibility over the sound of large engine noise.
I had about 1000 pounds of small signal and 400 Hz power transformers that came with the 100,000 tubes I got from the estate of a WWII era collector. I tested several dozen of these and found that all were useless above 10 KHz. Possibly of some use in a guitar amp, but I gave all of mine to the metal scrapper.
There were racks full of military spares dating from 1939 to the mid 60's. Some of it was so well constructed that it made an old Tektronix scope look cluttered. I parted out several hundred pounds of the modules for the ceramic tube sockets, terminal boards, and oil filled caps, but I had to give it all away when I recently moved. Again, most of the transformers had severe loss above 10 KHz.
That would make 100% sense TubeLab, for where I got them from many of his parts come from military gear + old radios.
I choose to build EMI's 47 Line Amplifier from their REDD console + use it as a Mic Preamp. I choose this build because it is a tube-project that is not based around the 12xx7 family but the ef86. *I have the valves included the (2) OA2's which I DO want to use in the deisgn. My 1st design-question is:
1) How do we impliment a VU Meter into the Output of the design?
*I will end up purchasing Sowter's transformers for this build the 9970+9980 if we can't get any of the transformers I have to fit/work.
**But before anyone jumps on me and says "oh we can't get the transformers you have available to fit that easily", let's focus on explaining how to implement a Meter into the design. I read that if I don't use a buffer it will add distortion to the signal--so the signal is usually copied-over w/ an Op Amp to run specifically into the Meter. I'll post a few different versions of the schematic. First one is a rough break-down of the design
Original Schematic of the REDD47 Line Amplifier
Re-draw of the original schematic *8k2 NOT 82k for the Plate Resistor.
I believe this is Gyraf's take on the design w/ added Constant-Current Devices on the cathodes of both tubes.
*I wouldn't mind trying-out the Constant-Current Devices. Ideally if I could flip a switch to turn either on or off would be killer (and simply to implement). I have read that the sound of this amplifier comes from the regulated HT, so I'm quite interested in hearing it w/ the Constant-Current Devices, just unfamiliar how I would add the VU-meter into the design.
Here is a pic of the large Volume Unit Meter. *(the 2-smaller meters are current meters & I won't worry about them right now -- even though I would like to use them in the future -- I would just need to figure out where they would actually be useful to use I stead of just being used for looks.)
1) How do we impliment a VU Meter into the Output of the design?
*I will end up purchasing Sowter's transformers for this build the 9970+9980 if we can't get any of the transformers I have to fit/work.
**But before anyone jumps on me and says "oh we can't get the transformers you have available to fit that easily", let's focus on explaining how to implement a Meter into the design. I read that if I don't use a buffer it will add distortion to the signal--so the signal is usually copied-over w/ an Op Amp to run specifically into the Meter. I'll post a few different versions of the schematic. First one is a rough break-down of the design
An externally hosted image should be here but it was not working when we last tested it.
Original Schematic of the REDD47 Line Amplifier
An externally hosted image should be here but it was not working when we last tested it.
Re-draw of the original schematic *8k2 NOT 82k for the Plate Resistor.
An externally hosted image should be here but it was not working when we last tested it.
I believe this is Gyraf's take on the design w/ added Constant-Current Devices on the cathodes of both tubes.
An externally hosted image should be here but it was not working when we last tested it.
*I wouldn't mind trying-out the Constant-Current Devices. Ideally if I could flip a switch to turn either on or off would be killer (and simply to implement). I have read that the sound of this amplifier comes from the regulated HT, so I'm quite interested in hearing it w/ the Constant-Current Devices, just unfamiliar how I would add the VU-meter into the design.
Here is a pic of the large Volume Unit Meter. *(the 2-smaller meters are current meters & I won't worry about them right now -- even though I would like to use them in the future -- I would just need to figure out where they would actually be useful to use I stead of just being used for looks.)
An externally hosted image should be here but it was not working when we last tested it.
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*for the VU meter I found this info from a GS thread *I'll post the GS thread link below:
"here is the voltage you need:
Volume Unit (VU) defined:*The reading of the volume indicator shall be 0 VU when it is connected to an AC voltage equal to 1.23 Volts RMS (equal to +4*dBu) at 1000*cycles per second."
https://www.gearslutz.com/board/geekslutz-forum/671521-wiring-analog-vu-meter.html
"here is the voltage you need:
Volume Unit (VU) defined:*The reading of the volume indicator shall be 0 VU when it is connected to an AC voltage equal to 1.23 Volts RMS (equal to +4*dBu) at 1000*cycles per second."
https://www.gearslutz.com/board/geekslutz-forum/671521-wiring-analog-vu-meter.html
Hmmm, 1.23 volts is referenced at "0" on the Meter.. Do you guys think I should use it on the Output of the REDD47 Mic Pre, the Input of the Pre, or at the end of the entire signal-chain if I were able to build multiple units (the ef86 REDD47 being one of those units [the Mic Pre] in the "Ultimate" Channel Strip this Thread was original written about creating).
If you read Wigwam Jones's post on Page-1 he's build-philosophy is exactly as my own... Take what you have + make soemtbing of it... If it wasn't intend or designed for such purpose -- all the more better! 😉
Jazbo8, I'll draw up a Block-Diagram -- that is an excellent idea for me to keep it simple since I lack the engineering knowledge to draw out the full schematic. *plus I really enjoy Box-Diagrams as they allow me to express my full-idea w/o being limited by my lack of knowledge
An externally hosted image should be here but it was not working when we last tested it.
Got the Transformers. Input is 10:1 + secondaries are 5:1 + 2:1 (hp)
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