SE Z5600a II schematic
- Thread starter Tim Campbell
- Start date
Help Support GroupDIY Audio Forum:
I emailed SE to request the schematics, I'll post whatever they provide.
I purchased one of these mics used a couple years back. It worked fine for a while, but one day in the middle of a session, it stopped working.
I have taken this mic to two different shops, and both wanted an absurd amount of money to repair the mic...more than I paid for it in the first place. I have tried selling the mic on eBay as a parts mic, and it has sold twice, but both times the sale ended up not going through (the first guy changed his mind, the second guy never paid up). At this point, I don't feel good about trashing the mic, I can't get anyone to repair it for a reasonable price, and selling it has been problematic.
So I'm entertaining the idea of attempting my own repair, and hoping that someone here can help guide me through this process. I am not an electronics repair tech, although I know a few principles and generally understand what some of the main components do. I've soldered a few things...I'm not awesome at it, but I can do it. I assembled a couple of my own DIY mic kits from Bumblebee Mics, and I've also done my own mods to a spare SM57. The thing I lack the most is understanding of how to pinpoint the exact problem.
A little more background on this unit...
I was stupidly running phantom power while using the mic, and I believe (not certain) that might have been what fried it. I've been told that phantom power generally doesn't hurt mics like this, but the manual says to not run phantom power on it. There was no warning that something was wrong before it happened. It was working fine one minute. I walked away for a couple minutes, came back, and it wasn't working anymore. When I say "not working" what I mean is there was no signal coming from the mic whatsoever. Since I was out of the room when "it" happened, I'm not sure if the mic generated any noise or pops, cracks, sizzles, etc. when it broke. After it broke, I would occasionally get a little bit of a shock from touching the power supply while it was powered on.
The first shop I took it to did some work on it, but eventually told me it was "beyond economical repair". However, that shop was going out of business at the time. They shuttered their doors about 2 weeks after returning it to me. When they handed it back to me, they included a bag of small parts, and didn't really explain to me much about what they were. I opened the PSU and could tell that they had replaced a few things based on solder points (I think you guys call these pads in the electronics world?) that looked freshly soldered, so I suspect that the parts they gave me are the old parts they took out. I can match up MOST of the spare parts they gave me with the fresh solder points, however there are a couple parts that don't seem to match up with anything, so I'm not sure if they had gotten halfway through the repair and then stopped, or possibly swapped some parts out in the mic as well.
The second shop I sent it to was Advanced Musical Repair in LA. This shop was recommended to me by SE as their only certified shop in the US. This shop claimed that the mic had a bad capsule and needed some minor work in the PSU. They quoted me about $550 to repair the mic, which was more than I paid for it in the first place. That being the case I decided to not have them repair the mic, and they sent it back to me.
I've done a little bit of my own troubleshooting after having these shops look at it. I've checked a few things on the PSU with a multimeter, and can't find any open shorts, but I also know that some components have to be checked in a specific manner to verify if they are working, so I'm sure my investigation with the multimeter wasn't very thorough or accurate. The PSU does power on, and the shocking it was giving me after it broke is not happening anymore. I suspect this is one of the things the first shop repaired.
There are 2 spots on the board in the PSU where it looks like there should be components installed, but there's nothing there. These are labeled 180V and 6V. I am not sure what these designations mean, which is why I've requested a schematic from SE, or maybe someone else on here can help me understand. (see photos)
On the mic, I have removed the housing to inspect the inside. There doesn't appear to be any visual damage on the inside of the mic, but I haven't checked anything on it with a multimeter. When the PSU/mic is powered on the tube does not glow. I tried swapping the tube to one that I know is working, and that one doesn't glow either. I have tested the 8-pin cable with a multimeter and that seems to be working fine, so that all leads me to believe that power is not getting to the mic and it's probably a result of something still being wrong in the PSU.
I'm skeptical of the second shop's claim that the mic needed a new capsule. I didn't do any testing on that, mostly because I don't really know how to test it with the current state of the unit. Normally a bad capsule will still generate some sound, and I know how to test it in that condition, but when the mic is not producing any signal whatsoever, I'm not sure how they came to that conclusion. If I can get this mic working again, I would probably want to replace the capsule with a K47 capsule anyway, but I want to make sure I can solve the other problems first before I drop the money on an upgrade.
I am also curious if replacing the transformer would improve the sound of the mic. I believe the transformer is the small blue box labeled "Chansin" on the PSU board? I wouldn't know where to start in selecting an appropriate replacement for the transformer, so maybe someone can help me out with that as well. Again, this is only if I can get the mic working again first.
Anyway, I know this is a long post, and I'm reaching a little, but I appreciate any help or insight that anyone can offer.
Thanks!
I have taken this mic to two different shops, and both wanted an absurd amount of money to repair the mic...more than I paid for it in the first place. I have tried selling the mic on eBay as a parts mic, and it has sold twice, but both times the sale ended up not going through (the first guy changed his mind, the second guy never paid up). At this point, I don't feel good about trashing the mic, I can't get anyone to repair it for a reasonable price, and selling it has been problematic.
So I'm entertaining the idea of attempting my own repair, and hoping that someone here can help guide me through this process. I am not an electronics repair tech, although I know a few principles and generally understand what some of the main components do. I've soldered a few things...I'm not awesome at it, but I can do it. I assembled a couple of my own DIY mic kits from Bumblebee Mics, and I've also done my own mods to a spare SM57. The thing I lack the most is understanding of how to pinpoint the exact problem.
A little more background on this unit...
I was stupidly running phantom power while using the mic, and I believe (not certain) that might have been what fried it. I've been told that phantom power generally doesn't hurt mics like this, but the manual says to not run phantom power on it. There was no warning that something was wrong before it happened. It was working fine one minute. I walked away for a couple minutes, came back, and it wasn't working anymore. When I say "not working" what I mean is there was no signal coming from the mic whatsoever. Since I was out of the room when "it" happened, I'm not sure if the mic generated any noise or pops, cracks, sizzles, etc. when it broke. After it broke, I would occasionally get a little bit of a shock from touching the power supply while it was powered on.
The first shop I took it to did some work on it, but eventually told me it was "beyond economical repair". However, that shop was going out of business at the time. They shuttered their doors about 2 weeks after returning it to me. When they handed it back to me, they included a bag of small parts, and didn't really explain to me much about what they were. I opened the PSU and could tell that they had replaced a few things based on solder points (I think you guys call these pads in the electronics world?) that looked freshly soldered, so I suspect that the parts they gave me are the old parts they took out. I can match up MOST of the spare parts they gave me with the fresh solder points, however there are a couple parts that don't seem to match up with anything, so I'm not sure if they had gotten halfway through the repair and then stopped, or possibly swapped some parts out in the mic as well.
The second shop I sent it to was Advanced Musical Repair in LA. This shop was recommended to me by SE as their only certified shop in the US. This shop claimed that the mic had a bad capsule and needed some minor work in the PSU. They quoted me about $550 to repair the mic, which was more than I paid for it in the first place. That being the case I decided to not have them repair the mic, and they sent it back to me.
I've done a little bit of my own troubleshooting after having these shops look at it. I've checked a few things on the PSU with a multimeter, and can't find any open shorts, but I also know that some components have to be checked in a specific manner to verify if they are working, so I'm sure my investigation with the multimeter wasn't very thorough or accurate. The PSU does power on, and the shocking it was giving me after it broke is not happening anymore. I suspect this is one of the things the first shop repaired.
There are 2 spots on the board in the PSU where it looks like there should be components installed, but there's nothing there. These are labeled 180V and 6V. I am not sure what these designations mean, which is why I've requested a schematic from SE, or maybe someone else on here can help me understand. (see photos)
On the mic, I have removed the housing to inspect the inside. There doesn't appear to be any visual damage on the inside of the mic, but I haven't checked anything on it with a multimeter. When the PSU/mic is powered on the tube does not glow. I tried swapping the tube to one that I know is working, and that one doesn't glow either. I have tested the 8-pin cable with a multimeter and that seems to be working fine, so that all leads me to believe that power is not getting to the mic and it's probably a result of something still being wrong in the PSU.
I'm skeptical of the second shop's claim that the mic needed a new capsule. I didn't do any testing on that, mostly because I don't really know how to test it with the current state of the unit. Normally a bad capsule will still generate some sound, and I know how to test it in that condition, but when the mic is not producing any signal whatsoever, I'm not sure how they came to that conclusion. If I can get this mic working again, I would probably want to replace the capsule with a K47 capsule anyway, but I want to make sure I can solve the other problems first before I drop the money on an upgrade.
I am also curious if replacing the transformer would improve the sound of the mic. I believe the transformer is the small blue box labeled "Chansin" on the PSU board? I wouldn't know where to start in selecting an appropriate replacement for the transformer, so maybe someone can help me out with that as well. Again, this is only if I can get the mic working again first.
Anyway, I know this is a long post, and I'm reaching a little, but I appreciate any help or insight that anyone can offer.
Thanks!
Attachments
Well, there's not much to go on, without having done any sort of measurements at all. None of us here are mind-readers.
That being said, right under this box i can see a first "related thread", which should offer at least a starting.
https://groupdiy.com/threads/noob-needs-help-with-z5600a-ii-mic-repair.84465/
That being said, right under this box i can see a first "related thread", which should offer at least a starting.
https://groupdiy.com/threads/noob-needs-help-with-z5600a-ii-mic-repair.84465/
Matt Nolan
Well-known member
I think that little blue box is a relay. The audio transformer will be inside the metal chamber at the bottom end of the microphone.
The suspected missing components on the PSU board are most likely probe points for testing during manufacture or servicing.
The suspected missing components on the PSU board are most likely probe points for testing during manufacture or servicing.
NoisyIndividual
Well-known member
Well you have clearly stated "the tube does not glow".
Which implies either the heater circuit is not functioning, or you just can't see the glowing filament.
If the tube remains stone cold, then yes, the tube does not glow, and that is where you need to start.
Which implies either the heater circuit is not functioning, or you just can't see the glowing filament.
If the tube remains stone cold, then yes, the tube does not glow, and that is where you need to start.
terry setter
Well-known member
- Joined
- Nov 17, 2013
- Messages
- 177
The corner of the PS board where it says "180V" and appears to have a missing part might well have been a zener diode. If so, it's likely that there were two 90V zeners in series from the "180V" point to ground. If, when you heater voltage gets fixed, you see more than 180V for your B+ supply, omitting the zener would explain it.
There are three 60V Zeners in the PSU that set 180V and provide the 120V for the switched divider network for the pattern rotary switch from 0V - 120V. I’d check the filament pins of the tube for correct voltage - from the blurry schematic there’s a voltage regulator in the PSU which is probably a 7806 if you’re not getting filament voltage this may have blown.
Well that thread was interesting.
After I got past all the drama in the first few pages there was some useful info in there, especially regarding the transformer upgrades. Ironic that this thread posted fairly recently.
I left the mic powered up for about 30 minutes and it never got warm. To be honest I don't know enough to even know what the heater circuit is, or where it is on the unit. Googling turned up some info, but I would need someone to explain it to me like I'm a 5 year old, and I can't find anything like that.
Upon further visual examination of the mic, I did notice that the C4 capacitor looks like it's been removed. That must be the loose blue capacitor that was returned to me with the spare parts from the first shop. Not sure if that's part of the heater circuit.
Frankly all I'm taking away at this point is that this is something that is way beyond my knowledge & expertise, especially with an almost unreadable schematic. I do appreciate everyone taking some time to reply to me. Reading a few of the threads on this forum I now feel a little foolish in thinking that this is something that someone could walk me through considering my extremely limited knowledge on the subject. I think I'll continue searching for a local tech who could give me a second/third opinion on the cost of a professional repair, and if it is still too expensive then I'll try posting it for sale again. It might end up sitting on a shelf for a while longer before this unit begins it's next chapter of existence.
Perhaps if I get qualified to post the mic in the classified section I will do that...I seem to not be generating exposure to the right crowd in posting it on eBay. Seems like this community might be more interested in acquiring this kind of broken down stuff.
The filament supply comes in on pin 2 of the cable connector that connects the mic with the power supply, ground is pin 7, you should have 6V DC between 2 and 7 - no heater, no mic sound. No 6V regulator in the PSU, no heater. The heater power comes from the power supply. I would also refit the C4 capacitor. As Khron mentioned there’s a lot of stuff in the thread he linked.
The little blue box labelled “Chansin” is definitely a relay.
The coupling transformer is in the base of the microphone body in a round MU Metal case, not in the PSU box.
Running phantom into this mic will not hurt it - it’s transformer isolated. All that’ll happen is nothing as pin 2 and pin 3 carry the same voltage, subsequently not impacting the sound or circuitry on the microphone side of the transformer.
Phantom is designed to deliver only a few mA and a load of more than about 20mA will just drop the phantom voltage across the high resistance phantom feed resistors. The initial pre feed resistor voltage remains unaffected.
The parts on the bench :
the blue thing is a capacitor that is 100nF or 0.1uF that I think will be the old capacitor that goes from the cathode of the 1st tube stage to ground in parallel to a resistor and an electrolytic capacitor - from the photo of the board you supplied it would appear they’ve changed for a new one but I’d look at C4 capacitor and check it’s got either 104 (10 to the power of 4 ie 100,000 picofarad) or 100n, or 0.1uF - all mean the same thing, same value, different way of writing the value. Voltage should be the same. If not the correct value either get a new one or put the old one back. Having said that the capacitor could also have come from the power supply
The flat 3 pin device looks like a 7806 voltage regulator so I’d say they’ve changed that in the power supply.
You need to check if you’re getting 6 volts - look at your photos of the 6V and 180V points in the PSU box you queried about - these are the supply voltage test points - not missing parts there.
Just do the simple test with a DC Voltmeter make sure you’re getting those voltages. Be careful around the 180V. If the DC voltages are missing altogether you need to check the AC out from the transformer for that stage - the 180V DC is then derived from a bridge rectifier and then regulated by a trio of 60V Zener diodes, the 2/3 position for the pattern selector, the 3/3 position for the B+ for the tube. The 6V heater supply is derived from a bridge rectifier and regulated by a 7806 positive voltage regulator.
If there’s a missing AC voltage (after DC test) that will mean a blown transformer.
You will find this difficult if you can’t follow the schematic or know how a power supply logically works, but if you do the measurements of basic power first, someone here can maybe help you - also a clear photo of the regulator from the spare parts they gave back to you.
Does the panel light come on?
The way these mics work is really simple. To do any sort of work on this you’ll need some basic tools like a multimeter, good soldering iron with fine tips, desolder sucker, decent solder - 0.7mm a good size.
Get it working properly before you start worrying about replacing the transformer - serious size issues with fitting a new transformer unless you can get one that is small enough and the right profile to fit and is known to be better than the one installed - even then a bit of mechanical work involved. You can’t do improvements on a mic that’s not working.
Edit:
The value of capacitance 104 is the first 2 digits (10) multiplied by 10 to the power of 4 (10,000) = 10 x 10,000 = 100,000nF - the 3rd digit is your multiplier code. I didn’t make that quite clear before!
The coupling transformer is in the base of the microphone body in a round MU Metal case, not in the PSU box.
Running phantom into this mic will not hurt it - it’s transformer isolated. All that’ll happen is nothing as pin 2 and pin 3 carry the same voltage, subsequently not impacting the sound or circuitry on the microphone side of the transformer.
Phantom is designed to deliver only a few mA and a load of more than about 20mA will just drop the phantom voltage across the high resistance phantom feed resistors. The initial pre feed resistor voltage remains unaffected.
The parts on the bench :
the blue thing is a capacitor that is 100nF or 0.1uF that I think will be the old capacitor that goes from the cathode of the 1st tube stage to ground in parallel to a resistor and an electrolytic capacitor - from the photo of the board you supplied it would appear they’ve changed for a new one but I’d look at C4 capacitor and check it’s got either 104 (10 to the power of 4 ie 100,000 picofarad) or 100n, or 0.1uF - all mean the same thing, same value, different way of writing the value. Voltage should be the same. If not the correct value either get a new one or put the old one back. Having said that the capacitor could also have come from the power supply
The flat 3 pin device looks like a 7806 voltage regulator so I’d say they’ve changed that in the power supply.
You need to check if you’re getting 6 volts - look at your photos of the 6V and 180V points in the PSU box you queried about - these are the supply voltage test points - not missing parts there.
Just do the simple test with a DC Voltmeter make sure you’re getting those voltages. Be careful around the 180V. If the DC voltages are missing altogether you need to check the AC out from the transformer for that stage - the 180V DC is then derived from a bridge rectifier and then regulated by a trio of 60V Zener diodes, the 2/3 position for the pattern selector, the 3/3 position for the B+ for the tube. The 6V heater supply is derived from a bridge rectifier and regulated by a 7806 positive voltage regulator.
If there’s a missing AC voltage (after DC test) that will mean a blown transformer.
You will find this difficult if you can’t follow the schematic or know how a power supply logically works, but if you do the measurements of basic power first, someone here can maybe help you - also a clear photo of the regulator from the spare parts they gave back to you.
Does the panel light come on?
The way these mics work is really simple. To do any sort of work on this you’ll need some basic tools like a multimeter, good soldering iron with fine tips, desolder sucker, decent solder - 0.7mm a good size.
Get it working properly before you start worrying about replacing the transformer - serious size issues with fitting a new transformer unless you can get one that is small enough and the right profile to fit and is known to be better than the one installed - even then a bit of mechanical work involved. You can’t do improvements on a mic that’s not working.
Edit:
The value of capacitance 104 is the first 2 digits (10) multiplied by 10 to the power of 4 (10,000) = 10 x 10,000 = 100,000nF - the 3rd digit is your multiplier code. I didn’t make that quite clear before!
Last edited:
