Reading on Right Driver Tube P3: 1.80 VDC
Reading from GND to R10 (is that OK?): 1.81 VDC
So, it looks like the current I am getting there is 1.80/220 = 8.18 mA only
I'm torturing my child resistant SSE on my bench right now.
With garden variety Sylvania 12AT7, I have 2.24 and 1.81 on the cathodes.
Your numbers are fine.
Your problem lies elsewhere. Look really hard at your input wiring.
Win W5JAG
With garden variety Sylvania 12AT7, I have 2.24 and 1.81 on the cathodes.
Your numbers are fine.
Your problem lies elsewhere. Look really hard at your input wiring.
Win W5JAG
Agreed...what is the other channel?
Be nice to see better matching but looks ok
I still say swap opts...be good to rule that out or not.
Swap cables
Double check you don't have rca input grounded by accident
Be nice to see better matching but looks ok
I still say swap opts...be good to rule that out or not.
Swap cables
Double check you don't have rca input grounded by accident
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From all I have seen and judging by the voltage readings being Ok leads me to believe also that the input signal is being grounded somewhere.
Maybe at this stage you need to do a little p2p wiring of the left signal path into the driver tube at pin 2. It's only 2 resistors.
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Sent from my HTC One_M8 using Tapatalk
Sorry, I missed most of this thread. From what I can gather so far it seems that all of the tubes and surrounding circuitry is OK. As stated there must be a problem in the input wiring.
As stated measure the resistance from the center pin of each input jack to ground with the amp turned off. The readings should be nearly identical, and about 220K ohms if no volume pot is used. I don't see one in your picture. Equal to the volume pot rating if there is one.
If the dead channel reads very low, near zero there is a short on the wiring somewhere. If the dead channel reads very high, or infinite, there is an open circuit on that wiring.
If there is a problem, disconnect the wiring from the board, and measure at the board input to decide if the problem is on the board, or in the wiring.
You can also use the good wiring to test the dead channel. Disconnect the input wiring from the board, and connect the wiring from the good channel to the "bad" input on the board. Sound? Yes, the wiring is broken. No sound? The board is broken.
Wiring....first off check the cable from the dac to the amp.....wouldn't be the first time a cable broke at the worst possible moment.
Shorted wiring.... disconnect the wiring from the RCA connector and measure the resistance of the wiring, and the connector separately. Some cable with nylon insulation is prone to melting, and it can short out near where the soldering was done. A reversed center and shield swap, can cause these symptoms.
As stated measure the resistance from the center pin of each input jack to ground with the amp turned off. The readings should be nearly identical, and about 220K ohms if no volume pot is used. I don't see one in your picture. Equal to the volume pot rating if there is one.
If the dead channel reads very low, near zero there is a short on the wiring somewhere. If the dead channel reads very high, or infinite, there is an open circuit on that wiring.
If there is a problem, disconnect the wiring from the board, and measure at the board input to decide if the problem is on the board, or in the wiring.
You can also use the good wiring to test the dead channel. Disconnect the input wiring from the board, and connect the wiring from the good channel to the "bad" input on the board. Sound? Yes, the wiring is broken. No sound? The board is broken.
Wiring....first off check the cable from the dac to the amp.....wouldn't be the first time a cable broke at the worst possible moment.
Shorted wiring.... disconnect the wiring from the RCA connector and measure the resistance of the wiring, and the connector separately. Some cable with nylon insulation is prone to melting, and it can short out near where the soldering was done. A reversed center and shield swap, can cause these symptoms.
It is supposed to go to ground. The positive one is not supposed to be. Verify with the other good channel to ease your mind.
Yes take a ohm reading with amp off and nothing connected of both inputs hot to ground...Center of rca to outside jacket.
Thanks George, hope all is well with you guys and the move.
So today, I checked the Right channel terminals directly, across -ve and +ve and the reading is around 221K, so we should be good circuit-wise.
Checked the Right RCA IN/+ve to GND and there's a glitch there: it looks as if the connection is broken.
I then checked the +ve lead into the right RCA at the solder joint beneath and it's reading 221K fine.
Since this points to a dodgy RCA connector, I found another one from my salvage box, nearly killed it while extracting it, tested it but continuity was good.
I took the opportunity of examining the right channel +ve lead near the RCA connector and saw some wires frayed, so added some solder there to prevent any possibility of further shorting at this area.
Soldered back the +ve lead, the -ve lead and GND to the new RCA, wired up the old test media player, powered on the amp.
IT WORKS! 🙂
WE DID IT, GUYS!
Thanks a lot everyone for helping me and encouraging me along the way. It can get a bit disheartening not knowing what to do and how, but with patience and a willingness to learn, there's someone willing to help as well, so that's great!
It's a good feeling also to be able to follow the diagnosis procedures, so that in case I need to troubleshoot I can be more confident.
Here are a few mistakes to avoid for beginners so as not to go through the difficulties I did:
1. Ensure that you also do your mechanical layour properly. Case in point: in the chassis I re-used which you can see earlier in this thread, there were a lot of RCA-like holes. I re-used these for placing both the input RCA and the Speaker terminals because this allowed me not to have to drill the metal chassis.
What happened to us here was that I had some difficulties securing the RCA terminals there. Additionally, re-using these holes mean that one of set of my speaker terminals was near the RCA inputs.
There must be a Murphy's Law for tube amps or for mechanical mistakes, because one of the RCA input lugs rotated in place and then proceeded to touch the Speaker Terminal lug => Output (Higher Voltage as it's been through the amp) shorted to Input (which expects very small voltage).
This is where the channel went down.
2. If you are reusing salvaged parts, take some time to test these before integrating them. It's great to be able to salvage, but it's much less fun when you have to try to understand what went wrong in the circuit when in fact the salvaged part could be the culprit.
3. Take some time to learn about the Terminology and circuitry of tube amps. This is important because when you get help, you will then better understand what is referred to. I had some difficulty with this, but took some time to read in bed so that the concepts could be clearer for a troubleshooting session the next day.
4. Don't be afraid to ask questions and ask again for clarifications. Here again, there are a lot of knowledgeable people willing to help, but if things are not clear, ask more questions until they are clear enough to allow some diagnosis actions and repair/test actions.
5. Be Patient! There can be spells where no one is available to answer your questions. You can be discouraged. These both happened to me. If you check the date when the issue occured in this thread, it's been more than a year since I had the opportunity of listening to my SSE, maybe 2 years or more even. Recently though, some of you guys started replying, so I took time to put a maximum amount of effort into solving the issue.
So this build was only enjoyed for a very brief moment before it all went down and it took me a long time to re-build it, but thanks to you it was all possible. Good consolation: it worked the first time I made it, so there were no electronic or electrical errors.
Next up, I am going to connect it to the Totem Mites or else just do all the remaining mechanical work first.
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On second thought, the boy and the grill deserve listening to the tube amp for a while before considering further work on it 😛
Now we can truly celebrate. Everyone loves success stories and as you say you learned a lot along the way and now you will have to help someone else down the road with their build. That is the way it works around here.
A few pics and my listening configuration.
What I always wanted is to pair very high rate DSD files with Tube amplification.
My DAC is an iFi iDSD Nano, which through the latest firmware plays DSD256 even through DoP on Mac OS X.
I play files with Audirvana+, which is an audiophile player on Mac. I can also test using HQ Player, which I highly recommend, especially for its stellar sound and great real-time up-conversion to DSD capabilities (need a more powerful computer for this here).
My preferred source is native DSD (this is quite rare).
The arrangement plays through Totem Mites on DIY stands.
A few pics of the DAC connected to the Amp today:
Another view:
Tubes glowing in a darker environment:
Some of our listening impressions today:
- Great dynamics - guitar strings, percussions and drums generally, attacks
- Much presence, especially in the mid-range, enveloping sound
- A sense of flow, breathing
- Great separation
So, try adding tubes to your very high-rate native DSD setup!
What I always wanted is to pair very high rate DSD files with Tube amplification.
My DAC is an iFi iDSD Nano, which through the latest firmware plays DSD256 even through DoP on Mac OS X.
I play files with Audirvana+, which is an audiophile player on Mac. I can also test using HQ Player, which I highly recommend, especially for its stellar sound and great real-time up-conversion to DSD capabilities (need a more powerful computer for this here).
My preferred source is native DSD (this is quite rare).
The arrangement plays through Totem Mites on DIY stands.
A few pics of the DAC connected to the Amp today:
Another view:
Tubes glowing in a darker environment:
Some of our listening impressions today:
- Great dynamics - guitar strings, percussions and drums generally, attacks
- Much presence, especially in the mid-range, enveloping sound
- A sense of flow, breathing
- Great separation
So, try adding tubes to your very high-rate native DSD setup!
Forgot to mention, I am listening to the amp on its own dedicated line that the owner here installed for us graciously (he's an electrician by trade).
What kind and brand of tubes are you using? It does take a few hours, 100, for tubes to really show what they can do. It will sound even better a few days or weeks from now. Right now I have 8 or 10 working amps and this is my favorite. And it has gotten better after around 100 hours.
Electro-Harmonix KT-88
Russian (Svetlana or Sovtek) other tubes, except one is replaced by what I think is a generic Chinese driver tube.
ty ty
Haven't done much else the rest of the day (had a couple of bathroom breaks and ate something, made a cocktail for us) 😀