I am about half way through writing up the tutorial and would like to ask those interested in building this kit if they currently have any of the below type of test equipment to use during the build. This will help me write up the tutorial in a manner that will be helpful to most inexperienced builders.
Do you have any of the following:
1) Variac (to slowly power up a new device)
2) Dim bulb tester (to act as a fail safe during initial power up)
3) A multi-meter (DMM) with ability to measure capacitor values
4) A multi-meter (DMM) with the ability to measure and verify small bi-polar transistors
5) A multi-meter (DMM) with the ability to measure diodes (most multi-meters can do this, some don't
6) A vacuum tube tester with a socket to test small 7 pin tubes.
7) Two multi-meters (DMMs) so you can monitor two different voltages during power up (B+ and heaters)
8) Four minigrabber to banana plug test leads: For clipping to PCB for power up voltage tests (see link below): https://www.mouser.com/ProductDetail/Pomona-Electronics/3782-36-2?qs=sGAEpiMZZMtTOasXncsdUSyEpyO6wEB17zCnCsmeGwU=
Just trying to get an idea as to what to include or not include the writeup. Thanks. Bill
Bill, the answer to most of your questions is a 'No'. I have a multi meter, it's the most basic free one that we got some years ago as the door prize...
I went ahead and ordered a kit too. Green board version I think though. Oops.
I don't work on old equipment really so none of the advanced stuff. Probably have a few dmms around here including the harbor freight ones that I think have transistor testing capability. Have DATS so can measure caps. I probably have everything to setup the dim bulb tester besides the bulbs.
Just my gueas but I think that most folks don't have a fraction of what you listed Bill. A basic DMM is probably a safe bet. A variac... high probability not. A tube tester... no way. Those cheap give-away and Harbor Freight meters that do have capacitance and BJT measurements are questionable at best. Luckily this tube amp project doesn't have a high B+ voltage.
Thanks for the responses on test equipment. I'll write up the tutorial based on someone using a single, cheap multi-meter. One item I forgot to ask about is whether or not you have a kill-o-watt meter. Many homeowners purchase these inexpensvie meters to check appliance usage around the house. According to my meter, when the 6J1 preamp is plugged in and running, it consumes 6W or .08 amps of current from the wall socket at 121VAC. You should get something similar when you power it up with the Jamico wall wart. If not, you know that something is wrong and that you should power down quickly and double check your circuit.
that seems cheap enough to add. But is there any better more specialized tool that can be used to check the power draw - that can be used further for otehr elctronic projects?
A decent multimeter will be able to measure current draw up to 10A.
A few multimeters I have used and can recommend over the harbor freight freebies are the HT118a (sold under a lot of different names), and the aneng AN8008.
The HT118a is a great starter meter that illuminates the probe locations needed for the selected setting. This can be very handy if you are new.
The AN8008 is handy in that it has a square wave function generator built in.
I have used a lot of meters in my 20 year career in automotive electronics. I firmly believe that the 2 recommended meters will do anything needed on this project. If you want me to recommend something locally available or budget specific please shoot me a PM or start a new thread. I want to be respectful and not derail this thread.
Do you have any of the following:
1) Variac (to slowly power up a new device)
2) Dim bulb tester (to act as a fail safe during initial power up)
3) A multi-meter (DMM) with ability to measure capacitor values
4) A multi-meter (DMM) with the ability to measure and verify small bi-polar transistors
5) A multi-meter (DMM) with the ability to measure diodes (most multi-meters can do this, some don't
6) A vacuum tube tester with a socket to test small 7 pin tubes.
7) Two multi-meters (DMMs) so you can monitor two different voltages during power up (B+ and heaters)
8) Four minigrabber to banana plug test leads: For clipping to PCB for power up voltage tests (see link below): https://www.mouser.com/ProductDetail/Pomona-Electronics/3782-36-2?qs=sGAEpiMZZMtTOasXncsdUSyEpyO6wEB17zCnCsmeGwU=
1) Nope, I let the smoke out all at once not a little at a time.
2) easy enough to build
3) yes, and dats
4) TC1 multi function tester
5) yep, plus the above
6) ugotabekiddingme
7) yep
8) No, been wanting to get some for a while, next Mouser order
Do you have any of the following:
1) Variac (to slowly power up a new device)
2) Dim bulb tester (to act as a fail safe during initial power up)
3) A multi-meter (DMM) with ability to measure capacitor values
4) A multi-meter (DMM) with the ability to measure and verify small bi-polar transistors
5) A multi-meter (DMM) with the ability to measure diodes (most multi-meters can do this, some don't
6) A vacuum tube tester with a socket to test small 7 pin tubes.
7) Two multi-meters (DMMs) so you can monitor two different voltages during power up (B+ and heaters)
8) Four minigrabber to banana plug test leads: For clipping to PCB for power up voltage tests (see link below): https://www.mouser.com/ProductDetail/Pomona-Electronics/3782-36-2?qs=sGAEpiMZZMtTOasXncsdUSyEpyO6wEB17zCnCsmeGwU=
1) Nope, I let the smoke out all at once not a little at a time.
2) easy enough to build
3) yes, and dats
4) TC1 multi function tester
5) yep, plus the above
6) ugotabekiddingme
7) yep
8) No, been wanting to get some for a while, next Mouser order
Thanks for the info. You will really like the minigrabbers. They make multiple meter measurements so much easier. Since you have meters to test capacitance, diodes, and transistors, I would recommend testing each part before mounting to verify the value, polarity, and mounting orientation, especially the transistors and diodes. This is what I do and while many might regard this as overkill, I find that it is much easier to find a bad part before rather than after I solder it in place.
I got a Kaiweets test lead kit for Christmas and I love it. They are modular, pretty pliable, and surprisingly low impedance. The mini grabbers are great. I put some heat shrink on the thin long tipped probes so only a fraction of a mm is exposed. That greatly reduces the chance of shorting anything as I'm measuring transistor voltages on live circuitboards.
@Tom_S said:
I'm running mine into my DIY Gainclone amp, if that counts.
You mentioned in an earlier post building a Pass F6, do you still have that? I have the PCB boards and transformers and it will be my first "real" build sometime this year.
@Tom_S said:
I'm running mine into my DIY Gainclone amp, if that counts.
You mentioned in an earlier post building a Pass F6, do you still have that? I have the PCB boards and transformers and it will be my first "real" build sometime this year.
Yep - still have that. I should probably fire it up again - maybe even put it on the test bench. I should test the Gainclone too. I really just need to retire so I can play with all my toys, but that's still a few years away.
@6thplanet said:
Can't adjust some values and make a phono pre out of those kits?
That's way beyond my skill set! I have to have someone more qualified do the real engineerin'. But I'm restoring a Pioneer SX-828 right now and really like the sound of the phono preamp. I found the same board on eBay for $16 and wondered if I could turn it into a stand-alone unit. It only needs +25v and we just happen to have that in this 6J1 preamp.
You might be able to get enough gain (45+ dB) from that particular tube with just some resistor changes. But you also need to impliment the RIAA EQ. Done passively that throws away a bunch of total gain. Might not be possible without adding another gain stage or two.
Two kits piggy-backed? One to apply the curve, and the other to boost it to needed level? Looks like the needed curve is not far off a straight slope starting at 20hz (+20db) down to 20khz (-20db). ~4db/octave... interesting. So factoring in needed gain ~ +66db down to +26db (if average gain was +46db)? Or am I missing something?
It appears often the curve is split into two slopes with the first starting at ~50hz down to a flat between around 500hz-2khz before the next slope to 20k. That works out closer to 6db/octave for each so that makes a little more sense. Though I wonder if each slope would need to be applied by splitting into seperate gain stages. I'm way out of my element here so I'll stop to take the shoe out of my mouth.
For some reason, I cannot seem to find a 12vac 500ma ac to ac power supply at Mouser. Surely they have it. It would be simple to ad to the Mouser order sans paying s&h on one item from Jameco.
Comments
I am about half way through writing up the tutorial and would like to ask those interested in building this kit if they currently have any of the below type of test equipment to use during the build. This will help me write up the tutorial in a manner that will be helpful to most inexperienced builders.
Do you have any of the following:
1) Variac (to slowly power up a new device)
2) Dim bulb tester (to act as a fail safe during initial power up)
3) A multi-meter (DMM) with ability to measure capacitor values
4) A multi-meter (DMM) with the ability to measure and verify small bi-polar transistors
5) A multi-meter (DMM) with the ability to measure diodes (most multi-meters can do this, some don't
6) A vacuum tube tester with a socket to test small 7 pin tubes.
7) Two multi-meters (DMMs) so you can monitor two different voltages during power up (B+ and heaters)
8) Four minigrabber to banana plug test leads: For clipping to PCB for power up voltage tests (see link below): https://www.mouser.com/ProductDetail/Pomona-Electronics/3782-36-2?qs=sGAEpiMZZMtTOasXncsdUSyEpyO6wEB17zCnCsmeGwU=
Just trying to get an idea as to what to include or not include the writeup. Thanks. Bill
You’re good to go, Ani!
Thanks Tom!
Bill, the answer to most of your questions is a 'No'. I have a multi meter, it's the most basic free one that we got some years ago as the door prize...
I might be the worst case scenario.... :
I went ahead and ordered a kit too. Green board version I think though. Oops.
I don't work on old equipment really so none of the advanced stuff. Probably have a few dmms around here including the harbor freight ones that I think have transistor testing capability. Have DATS so can measure caps. I probably have everything to setup the dim bulb tester besides the bulbs.
Just my gueas but I think that most folks don't have a fraction of what you listed Bill. A basic DMM is probably a safe bet. A variac... high probability not. A tube tester... no way. Those cheap give-away and Harbor Freight meters that do have capacitance and BJT measurements are questionable at best. Luckily this tube amp project doesn't have a high B+ voltage.
Thanks for the responses on test equipment. I'll write up the tutorial based on someone using a single, cheap multi-meter. One item I forgot to ask about is whether or not you have a kill-o-watt meter. Many homeowners purchase these inexpensvie meters to check appliance usage around the house. According to my meter, when the 6J1 preamp is plugged in and running, it consumes 6W or .08 amps of current from the wall socket at 121VAC. You should get something similar when you power it up with the Jamico wall wart. If not, you know that something is wrong and that you should power down quickly and double check your circuit.
https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU
that seems cheap enough to add. But is there any better more specialized tool that can be used to check the power draw - that can be used further for otehr elctronic projects?
A UPS with a display panel showing load, voltage etc . . . can use it on your PC as well or a pellet stove or . . .
Nope, I'll ignore all the testing and smash the POTA button.
I ordered some (probably knockoff) GE tubes to swap in, so the factory ones can be my lab mice.
A decent multimeter will be able to measure current draw up to 10A.
A few multimeters I have used and can recommend over the harbor freight freebies are the HT118a (sold under a lot of different names), and the aneng AN8008.
The HT118a is a great starter meter that illuminates the probe locations needed for the selected setting. This can be very handy if you are new.
The AN8008 is handy in that it has a square wave function generator built in.
I have used a lot of meters in my 20 year career in automotive electronics. I firmly believe that the 2 recommended meters will do anything needed on this project. If you want me to recommend something locally available or budget specific please shoot me a PM or start a new thread. I want to be respectful and not derail this thread.
1) Nope, I let the smoke out all at once not a little at a time.
2) easy enough to build
3) yes, and dats
4) TC1 multi function tester
5) yep, plus the above
6) ugotabekiddingme
7) yep
8) No, been wanting to get some for a while, next Mouser order
Thanks for the info. You will really like the minigrabbers. They make multiple meter measurements so much easier. Since you have meters to test capacitance, diodes, and transistors, I would recommend testing each part before mounting to verify the value, polarity, and mounting orientation, especially the transistors and diodes. This is what I do and while many might regard this as overkill, I find that it is much easier to find a bad part before rather than after I solder it in place.
I got a Kaiweets test lead kit for Christmas and I love it. They are modular, pretty pliable, and surprisingly low impedance. The mini grabbers are great. I put some heat shrink on the thin long tipped probes so only a fraction of a mm is exposed. That greatly reduces the chance of shorting anything as I'm measuring transistor voltages on live circuitboards.
Balanced 'simple tube linestage' kit recommendations ?
I want to go fully balanced, so that the only thing humming in my room is me
It could be done with input & output transformers.
Little teeny ones?
Autobots, roll out....
InDIYana Event Website
--
http://www.vac-amps.com/productPages/StatmentLinePreamp.html
When do we get to the power amp
I'm running mine into my DIY Gainclone amp, if that counts.
I'm now considering adding a phono stage from a vintage Pioneer receiver.
You mentioned in an earlier post building a Pass F6, do you still have that? I have the PCB boards and transformers and it will be my first "real" build sometime this year.
Can't adjust some values and make a phono pre out of those kits?
Yep - still have that. I should probably fire it up again - maybe even put it on the test bench. I should test the Gainclone too. I really just need to retire so I can play with all my toys, but that's still a few years away.
That's way beyond my skill set! I have to have someone more qualified do the real engineerin'. But I'm restoring a Pioneer SX-828 right now and really like the sound of the phono preamp. I found the same board on eBay for $16 and wondered if I could turn it into a stand-alone unit. It only needs +25v and we just happen to have that in this 6J1 preamp.
You might be able to get enough gain (45+ dB) from that particular tube with just some resistor changes. But you also need to impliment the RIAA EQ. Done passively that throws away a bunch of total gain. Might not be possible without adding another gain stage or two.
Two kits piggy-backed? One to apply the curve, and the other to boost it to needed level? Looks like the needed curve is not far off a straight slope starting at 20hz (+20db) down to 20khz (-20db). ~4db/octave... interesting. So factoring in needed gain ~ +66db down to +26db (if average gain was +46db)? Or am I missing something?
https://en.wikipedia.org/wiki/RIAA_equalization
It appears often the curve is split into two slopes with the first starting at ~50hz down to a flat between around 500hz-2khz before the next slope to 20k. That works out closer to 6db/octave for each so that makes a little more sense. Though I wonder if each slope would need to be applied by splitting into seperate gain stages. I'm way out of my element here so I'll stop to take the shoe out of my mouth.
Found this:
https://sound-au.com/project06.htm
https://sound-au.com/project80.htm
For some reason, I cannot seem to find a 12vac 500ma ac to ac power supply at Mouser. Surely they have it. It would be simple to ad to the Mouser order sans paying s&h on one item from Jameco.
I assumed the cheap 12 VDC output would work?
546-BPD2E Mouser # for plug in 12VAC.
It needs AC input power not DC.