Eddie,
There has been a lot of distraction on this thread... Looking to the beginning of the thread, I think that you said that you removed the diodes, you do not need a jumper on the switch, in fact if you are not going to use the solid state diodes, you don't need the switch at all.
I would start with replacing the GZ34. As TubeLab said, you may as well give yourself some piece of mind and replace the two power supply capacitors as well.
Now, something that has not been mentioned, but may be a little beyond an absolute beginner, or might not be a suitable modification to this power supply, is to use a choke input filter or a very small value of the first capacitor to reduce the voltage. Not sure what the value of that open framed choke in the photo is, it might not be suitable for a choke input. However, someone might be able to assist with suggesting a suitable value of cap for a cLC filter. I am not the best with PSUII, but I think a value of around 3-4uF should work. Combined with a 5U4G, it would probably give you about 450V B+. I think that due to the high voltage out of the transformer, you will probably need a motor run type cap for this.
Or, you could take up TubeLab's kind offer.
I wish you all the best fixing this. I can tell you that it is a great amp and you will enjoy listening to it! Even more so since you will have done some trouble shooting and learned something along the way
George, I think that you have the admiration and respect of 99% of the people here, and I would hope, from 100% of your customers!
Chris
PS, you can take my post as the advice of a rookie!
There has been a lot of distraction on this thread... Looking to the beginning of the thread, I think that you said that you removed the diodes, you do not need a jumper on the switch, in fact if you are not going to use the solid state diodes, you don't need the switch at all.
I would start with replacing the GZ34. As TubeLab said, you may as well give yourself some piece of mind and replace the two power supply capacitors as well.
Now, something that has not been mentioned, but may be a little beyond an absolute beginner, or might not be a suitable modification to this power supply, is to use a choke input filter or a very small value of the first capacitor to reduce the voltage. Not sure what the value of that open framed choke in the photo is, it might not be suitable for a choke input. However, someone might be able to assist with suggesting a suitable value of cap for a cLC filter. I am not the best with PSUII, but I think a value of around 3-4uF should work. Combined with a 5U4G, it would probably give you about 450V B+. I think that due to the high voltage out of the transformer, you will probably need a motor run type cap for this.
Or, you could take up TubeLab's kind offer.
I wish you all the best fixing this. I can tell you that it is a great amp and you will enjoy listening to it! Even more so since you will have done some trouble shooting and learned something along the way
George, I think that you have the admiration and respect of 99% of the people here, and I would hope, from 100% of your customers!
Chris
PS, you can take my post as the advice of a rookie!
I apologize; I've been laying low for the last couple days hoping that some of the dust would settle on this thread. I'd like to thank you folks for helping me out! It's amazing how quickly one troublesome poster can take over a thread and nearly lead to its demise.
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In all seriousness, I'm really not looking to turn this transformer into an arc welder... I have a Lincoln in my garage that most definitely will make prettier welds than this Edcor one anyways. Besides, welding is typically performed with low volts, and a whole lot of amps.
To the couple of folks that have offered me potential solutions to get my amp working as is - thank you for ideas, but I think I'm going to try to get the amp working as designed before (if ever) I start changing things. To me, it just makes more sense to build it with a known configuration so that the rest of you (especially the designer) have a better idea of what's happening when I mess something up and ask troubleshooting questions.
Yesterday I soldered in my replacement diodes, and removed C1 and C2 from the board. I'm not planning to fire it up again until I get all the right components this time.
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Korneluk - thank you for our offer, but when I was ordering components, I did order at least one spare of each part number. I checked yesterday, and I do have a spare for each C1 and C2. C1 is a 47uF 500V electrolytic, and C2 is a 180uF 500v electrolytic, both rated at 85 deg C. Unless the caps that you're offering are different from what I already have, I'll pass... but thanks again!
Chrish - It's interesting that we both seem to be (or in your case, had) having problems with our JJ GX34s. Perhaps we're finding some common fault in their tube design or manufacturing process? Maybe I should order a replacement as you suggest, it certainly couldn't hurt.
TubeLab - I truly appreciate all the work that you've put into the design of your boards/amps. I believe that you've accomplished everything that you set out to do with the Simple SE - give folks like me an opportunity to build a tube amplifier relatively easily (and safely) while trying to learn about electronics. There are many of us out there who aren't electronics experts (my specialty happens to be in the U]mechanical[/U] field of rotor dynamics) who, without your willingness to help would never get to partake in this enjoyable hobby. The detail that you provide on your webpage (assy manual, parts list, etc), and the excellent support you provide on this forum is what led me to choose your design.
Please don't feel too responsible for what I've done. I was most likely too overzealous when ordering components that I ordered a larger power transformer than necessary, without realizing the potential consequences.
However, I will most definitely take you up on your offer for the transformer. As a minimum, please let me Paypal you some money to cover the shipping?... I believe that's the least I can do for all of your assistance.
I think that I'll also be ordering one of those inrush current limiters you mentioned. I certainly don't think it'll hurt, and I do know how bad inrush can be, especially on induction motors.
Thanks to everyone!
-Eddie
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In all seriousness, I'm really not looking to turn this transformer into an arc welder... I have a Lincoln in my garage that most definitely will make prettier welds than this Edcor one anyways. Besides, welding is typically performed with low volts, and a whole lot of amps.
To the couple of folks that have offered me potential solutions to get my amp working as is - thank you for ideas, but I think I'm going to try to get the amp working as designed before (if ever) I start changing things. To me, it just makes more sense to build it with a known configuration so that the rest of you (especially the designer) have a better idea of what's happening when I mess something up and ask troubleshooting questions.
Yesterday I soldered in my replacement diodes, and removed C1 and C2 from the board. I'm not planning to fire it up again until I get all the right components this time.
------------------------------------------
Korneluk - thank you for our offer, but when I was ordering components, I did order at least one spare of each part number. I checked yesterday, and I do have a spare for each C1 and C2. C1 is a 47uF 500V electrolytic, and C2 is a 180uF 500v electrolytic, both rated at 85 deg C. Unless the caps that you're offering are different from what I already have, I'll pass... but thanks again!
Chrish - It's interesting that we both seem to be (or in your case, had) having problems with our JJ GX34s. Perhaps we're finding some common fault in their tube design or manufacturing process? Maybe I should order a replacement as you suggest, it certainly couldn't hurt.
TubeLab - I truly appreciate all the work that you've put into the design of your boards/amps. I believe that you've accomplished everything that you set out to do with the Simple SE - give folks like me an opportunity to build a tube amplifier relatively easily (and safely) while trying to learn about electronics. There are many of us out there who aren't electronics experts (my specialty happens to be in the U]mechanical[/U] field of rotor dynamics) who, without your willingness to help would never get to partake in this enjoyable hobby. The detail that you provide on your webpage (assy manual, parts list, etc), and the excellent support you provide on this forum is what led me to choose your design.
Please don't feel too responsible for what I've done. I was most likely too overzealous when ordering components that I ordered a larger power transformer than necessary, without realizing the potential consequences.
However, I will most definitely take you up on your offer for the transformer. As a minimum, please let me Paypal you some money to cover the shipping?... I believe that's the least I can do for all of your assistance.
I think that I'll also be ordering one of those inrush current limiters you mentioned. I certainly don't think it'll hurt, and I do know how bad inrush can be, especially on induction motors.
Thanks to everyone!
-Eddie
G'Day Eddie,
Great to see that you have not lost hope!
With hindsight, I think that the trouble that I had with my JJ GZ34 may well have been the same problem as the diodes. That is, the kickback spike from the transformer when using the standby switch. This definitely fried the solid state diodes and I suspect that the GZ34 going at the same time is no coincidence. I think the spike caused some damage to the rectifier valve as well. Since removing the solid state diodes and removing the standby switch I have tried Sovtek 5AR4, Svetlana 5u3C (5U4GB), ancient used Hitachi 5U4GB, Mullard and AWV 5AS4s found at a movie prop warehouse, some other Russian rectifier valves that were way under spec (just to see if they worked) and have had ZERO issues. Have not tried a JJ rectifier again, so really cannot say if there is a problem with the JJ rectifiers. Would hate to give a product a bad name if it is not deserved.
I think that Tubelab has gone over and above what you would expect of a printed circuit board maker. I hope that "what goes around - comes around"!
God night
Chris
Great to see that you have not lost hope!
With hindsight, I think that the trouble that I had with my JJ GZ34 may well have been the same problem as the diodes. That is, the kickback spike from the transformer when using the standby switch. This definitely fried the solid state diodes and I suspect that the GZ34 going at the same time is no coincidence. I think the spike caused some damage to the rectifier valve as well. Since removing the solid state diodes and removing the standby switch I have tried Sovtek 5AR4, Svetlana 5u3C (5U4GB), ancient used Hitachi 5U4GB, Mullard and AWV 5AS4s found at a movie prop warehouse, some other Russian rectifier valves that were way under spec (just to see if they worked) and have had ZERO issues. Have not tried a JJ rectifier again, so really cannot say if there is a problem with the JJ rectifiers. Would hate to give a product a bad name if it is not deserved.
I think that Tubelab has gone over and above what you would expect of a printed circuit board maker. I hope that "what goes around - comes around"!
God night
Chris
Unlike some big corporations, or one that I can't name, I realize that without customers, you don't last long.
First, 355 people are laid off, the last of them were gone on Friday. Now at least 10 more that I know (and several more that I don't) have resigned out of disgust, or lack of faith in what is left of the business......
Sorry, "arc welder" is a generic term that I tend to use to describe anything that has the potential to make a lot of sparks, including some amplifiers that I have built. I understand the operation of a "Buzz Box" although all I have ever been able to do is melt things, not weld them.
eddiemeddiem, I have to go to the post office tomorrow to send out some boards, I will put the transformer in a flate rate box and send it. You can Paypal me the shipping after your amp is running.
Yes, it does to me too. One of the things that they try to teach you in those in house engineering classes is to limit the number of variables in any experiment, test or trial. Starting with a known working configuration will allow you to get your board working. You can see in the previously posted picture that I have a setup with the same tubes and transformers that you will be using. The only "unknown" is your board. Once the board is working, and that "unknown" becomes "known" then we can figure out how to make the big power transformer work.
Make sure that you do not have a jumper or switch connected to the SW1 terminals for the initial testing. Connecting these terminals turns on the solid state rectifiers, which raises the B+ voltage. The diodes can also provide far more current than a tube rectifier raising the possibility of a catastrophic event if there is a short on the board.
The caps that Jose is offering are significantly different. These are the large silver cans shown in some of my amplifier builds. They are reffered to as the "optional" or "supplemental" capacitor. I routinely add one of these to many of my amplifiers to improve the performance. It can be added to the capacitors on the board (after everything is working) as shown in the assembly instructions.
If you decide to make the big Edcor work they will be needed. PC board mounted capacitors for voltages above 500 volts are rare. To run the board above 500 volts the capacitors on the board are removed and two external capacitors are used. I have done this, but never drew up a diagram.
I believe that Chris's 5AR4 was zapped by the infamous standby switch. I have seen rectifier tubes spark out and still work fine many times. However it seems that the sparking that took place in Chris's tube was fatal. You state in post #9 that you saw a blue flash inside the tube, so there is a possibility that the 5AR4 could have been damaged.
The inrush in a tube amplifier is similar to the inrush in a motor. When a motor starts the initial surge is essentially the same as the current drawn if the rotor was locked, since it is initially not moving. When a tube amplifier is first switched on there are two surge mechanisms at work. All of the tube filaments are cold, and the resistance of cold Tungsten is about half of what it is hot. It goes up as the tubes heat up. All of the capacitors in the amp are discharged. Like a motor at start up their resistance is near zero. The poor rectifier tube is just waking up from a cold sleep and it is called upon to feed a very hungry capacitor. This is what leads to arguments about resistors, and I am not going there again, except to say that the inrush current limiter is a good idea. They didn't exist when those previously mentioned textbooks were written, so they are a modern solution to an old problem.
I have abused some JJ 5AR4's and some JJ EL34's with no issues. Other users have reported issues with all of their large power tubes. I think that if you read enough tube related information you will find something bad about all current production tubes. I have received 3 bad "Winged C" EL34's out of 4 ordered form a popular distributor who has a good reputation. I think ever vendor has a bad batch now and then. Back in the old days the tube companies sold off their bad lots to "second tier resellers" who rebranded them. I used to get GE 6L6GC's under the name "Thoro Test" in the late 1960's for 50 cents each! Now the junk seems to carry the same brand as the good ones and is usually found cheap on Ebay. Sometimes they wind up in distributor stock.
Well, sorry to keep you guys in suspense, but I was in China and Korea for the last week and a half, and didn't have any chance for updates. It was my first trip to Asia, and I really didn't know what to expect. It was definitely an eye-opener with respect to all the previous (western hemisphere) travel that I've done. I certianly enjoyed myself, and can't wait to go back.
Anyways, back to the subject at hand. About two weeks ago I recieved the recieved the "recycled" power transformer that TubeLab so graciously sent me. Obviously due to my trip, I didn't have a chance to get everything hooked up until tonight. First, I replaced both 500V capacitors, and proceed re-wiring everything according to the website. Then, it came time to install the tubes and flip the switch. Being cautious, I had ordered a new GZ34/5AR4, so I installed that along with the preamp tube, and two "cheaper" EL34 tubes (made in China, sort of ironic).
After switching on the power and waiting a minute or so at zero volume without anything appearing to be wrong, I powered up the CD, and pressed play. OK, still nothing has popped, or sparked, and the little "lights" in all four tubes are still glowing! Thinking that this is further than I've made it on all of my further attempts, I decided to turn up the volume a bit. The first thing that I noticed was how much more dimensional that music sounded compared to my conventional, solid state stuff... I was quite impressed.
After messing it up the first time, I ended up replacing the following:
- both rectifier diodes with the more heavy duty model
- both 500V capacitors with the same part number
- the original JJ GZ34/5AR4 rectifier with an equivalent Sovtek tube (still not sure if there's anyhing wrong with the originial, I haven't plugged it back in yet to test it)
- the "overkill" power transformer with the recycled one from TubeLab
So, I've been sitting here listening to the wonderful music through my new tube amp for the past hour or so, and have to admit, I'm nothing more than pleased. I admit, I was over-zealous when ordering parts and probably got a little aggressive due to my lack of knowledge/understanding and thought that I might be able to squeeze just a little more power out of the amplifier if I ordered just a little bit bigger transformer. I really can't complain, because I have certianly learned some about electronics, and it got me even more interested in this hobby. I hope this thread serves to document the learning process and troubles that I've gone through, and anyone in the future sourcing parts might be able to avoid the same mistake I did. At the least, hopefully they'll at least be able to go through this thread for the repairs...
TubeLab - I hope that I didn't hurt your feelings when I failed to get it working on my first couple of tries. If I did, I'm truly sorry. If it weren't for you, there's many of us out there that simply wouldn't have the ability/knowledge to enjoy this hobby (that you enjoy as a career also). Thank you very much!!!
I'd like to thank the folks on this forum for their troubleshooting support. I obviously couldn't have done it without you.
I've got a few pictures that I'll post soon, I just have to tear myself away from the laptop in front of the music, and go to the computer in the other room to download the pics off of my camera. Too bad I can't post an accurate reproduction of the music for you guys to hear!
Hey, who knows... I may get ambitious enough in the near future to get that other transformer working...
Talk to you guys very soon!
-Eddie
Anyways, back to the subject at hand. About two weeks ago I recieved the recieved the "recycled" power transformer that TubeLab so graciously sent me. Obviously due to my trip, I didn't have a chance to get everything hooked up until tonight. First, I replaced both 500V capacitors, and proceed re-wiring everything according to the website. Then, it came time to install the tubes and flip the switch. Being cautious, I had ordered a new GZ34/5AR4, so I installed that along with the preamp tube, and two "cheaper" EL34 tubes (made in China, sort of ironic).
After switching on the power and waiting a minute or so at zero volume without anything appearing to be wrong, I powered up the CD, and pressed play. OK, still nothing has popped, or sparked, and the little "lights" in all four tubes are still glowing! Thinking that this is further than I've made it on all of my further attempts, I decided to turn up the volume a bit. The first thing that I noticed was how much more dimensional that music sounded compared to my conventional, solid state stuff... I was quite impressed.
After messing it up the first time, I ended up replacing the following:
- both rectifier diodes with the more heavy duty model
- both 500V capacitors with the same part number
- the original JJ GZ34/5AR4 rectifier with an equivalent Sovtek tube (still not sure if there's anyhing wrong with the originial, I haven't plugged it back in yet to test it)
- the "overkill" power transformer with the recycled one from TubeLab
So, I've been sitting here listening to the wonderful music through my new tube amp for the past hour or so, and have to admit, I'm nothing more than pleased. I admit, I was over-zealous when ordering parts and probably got a little aggressive due to my lack of knowledge/understanding and thought that I might be able to squeeze just a little more power out of the amplifier if I ordered just a little bit bigger transformer. I really can't complain, because I have certianly learned some about electronics, and it got me even more interested in this hobby. I hope this thread serves to document the learning process and troubles that I've gone through, and anyone in the future sourcing parts might be able to avoid the same mistake I did. At the least, hopefully they'll at least be able to go through this thread for the repairs...
TubeLab - I hope that I didn't hurt your feelings when I failed to get it working on my first couple of tries. If I did, I'm truly sorry. If it weren't for you, there's many of us out there that simply wouldn't have the ability/knowledge to enjoy this hobby (that you enjoy as a career also). Thank you very much!!!
I'd like to thank the folks on this forum for their troubleshooting support. I obviously couldn't have done it without you.
I've got a few pictures that I'll post soon, I just have to tear myself away from the laptop in front of the music, and go to the computer in the other room to download the pics off of my camera. Too bad I can't post an accurate reproduction of the music for you guys to hear!
Hey, who knows... I may get ambitious enough in the near future to get that other transformer working...
Talk to you guys very soon!
-Eddie
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