Re the Transformer. I read on Dada Electronics to use a factor of 1.5 output watts to VA to size the transformer.
The size of the original transformer lends me to believe its more a 100 to 120va. When I bought the Strata I was told it was 80w RMS ( 80 x 1.5 = 120VA) which would be about right. But the now the literature says it is a 100w RMS so it should be around 150VA as its a single channel amp. Therefore a 160VA 35+35 should work well. This is what I gather but I'm not a 100% sure.
I got the sizing from a friend recommending using a 200VA. I could not source a 200VA, so got a 300VA instead that just managed to fit into 110m wide gap for the amp on the sub (109mm transformer). This should not put any pressure on the Transformer as its working well within its limits if the sizing is correct.
If there is any issues I will post a reply here. This is not a recommendation, just what I have done to change the 110v a/c sub to 240v a/c.
Cheers.
The size of the original transformer lends me to believe its more a 100 to 120va. When I bought the Strata I was told it was 80w RMS ( 80 x 1.5 = 120VA) which would be about right. But the now the literature says it is a 100w RMS so it should be around 150VA as its a single channel amp. Therefore a 160VA 35+35 should work well. This is what I gather but I'm not a 100% sure.
I got the sizing from a friend recommending using a 200VA. I could not source a 200VA, so got a 300VA instead that just managed to fit into 110m wide gap for the amp on the sub (109mm transformer). This should not put any pressure on the Transformer as its working well within its limits if the sizing is correct.
If there is any issues I will post a reply here. This is not a recommendation, just what I have done to change the 110v a/c sub to 240v a/c.
Cheers.
For those that have problems with these beasts the earlier models don't appear to be so well assembled.
I have a Stentor II. Purchased recently. All seemed OK. For some reason felt I should look inside to see how inputs are implemented.
Noticed two Mosfets (BUZ900) had been de-soldered (but not removed).
Re-soldered and ...a horrible LF hum (without any connections). Clearly previous owner had had the problem & had de-soldered & sold on to me as in good condition. Hmmm shame I've already left fleabay feedback.
Removed the Mosfets... and did rudimentary diode test on them and they seemd to turn on & off OK. The sub run ok minus the two Mosfets though presume lower power & stressing remaining.
Hmm tracked the circuit & noticed a few joints look iffy. Reflowed around the remaining transistors and re-installed the Mosfets. Hey-presto all is running fine.
Worth a try if you have the same problem.
I have a Stentor II. Purchased recently. All seemed OK. For some reason felt I should look inside to see how inputs are implemented.
Noticed two Mosfets (BUZ900) had been de-soldered (but not removed).
Re-soldered and ...a horrible LF hum (without any connections). Clearly previous owner had had the problem & had de-soldered & sold on to me as in good condition. Hmmm shame I've already left fleabay feedback.
Removed the Mosfets... and did rudimentary diode test on them and they seemd to turn on & off OK. The sub run ok minus the two Mosfets though presume lower power & stressing remaining.
Hmm tracked the circuit & noticed a few joints look iffy. Reflowed around the remaining transistors and re-installed the Mosfets. Hey-presto all is running fine.
Worth a try if you have the same problem.
Rel Storm 111
Need help with a Rel Storm 111, I had the same problem with the noisy front end transistors 6 years back, I replaced along with a 3 watt 12k resister.... sub worked flawlessly for another 6 years. New problem showed up, First the hookup - hi level unbalanced neutriks input for music and low level 0 db RCA input for movies I noticed that sub was no longer producing low end sound from Hi level input but for movies I still had low end sound.
Checked Neutriks connector- had speaker level sound on connector, yet when connected... nothing. One week later no sound at all. opened unit up, went right for the power supply, had + and - 60 volts dc rail voltage, no + and - 15 dc. checked the 2 5 amp soldered in fuses, good. couldn't readily see how the + and - 15 volts was being created. I substituted a + and - 15 volt bench supply, (tapped into the 4 wire cable that connects main PCB to filter PCB. I was able to get the lo level RCA input working again but hi level still no sound. So it seems like I have 2 problems... hi level input is dead and a bad + and - 15 volt supply. I can really use a hand with this one, does anyone have a schematic that would be a blessing at this point
Need help with a Rel Storm 111, I had the same problem with the noisy front end transistors 6 years back, I replaced along with a 3 watt 12k resister.... sub worked flawlessly for another 6 years. New problem showed up, First the hookup - hi level unbalanced neutriks input for music and low level 0 db RCA input for movies I noticed that sub was no longer producing low end sound from Hi level input but for movies I still had low end sound.
Checked Neutriks connector- had speaker level sound on connector, yet when connected... nothing. One week later no sound at all. opened unit up, went right for the power supply, had + and - 60 volts dc rail voltage, no + and - 15 dc. checked the 2 5 amp soldered in fuses, good. couldn't readily see how the + and - 15 volts was being created. I substituted a + and - 15 volt bench supply, (tapped into the 4 wire cable that connects main PCB to filter PCB. I was able to get the lo level RCA input working again but hi level still no sound. So it seems like I have 2 problems... hi level input is dead and a bad + and - 15 volt supply. I can really use a hand with this one, does anyone have a schematic that would be a blessing at this point
Spoke with rel service in CA. Very mean people. This info above is "proprietary". Ha. Design/source good amps in the first place. Otherwise it's like business within business.
I managed to squeeze out of the service guy that rel indeed replaces transistors to mje340 and mje350. 22k tiny resistor, and 15k 3 watt big resistor. Then the guy was like pay me 150$to repair this unit. I politely told him to go and F himself
circuit
Onlyclassab, I don't think the service manual is available publicly, but if I'm wrong, I would be grateful to know; you'll have to debug from the PCB.
In my unit, the 15V supplies originate from Q13 & Q14 which are likely to be regulated somehow from zener diodes. You'll have to sketch out the PCB traces around here to see what to test. It seems strange you've lost both + and - rails, you need to re-check this.
I haven't needed to work on my input/filter board and I have no wish to disassemble the unit unnecessarily. If your 'low' input is working, then it's likely only a relatively isolated part of the pre-amp circuit is suspect. If you're going to disassemble the unit for testing/repairs, then you could try posting very crisp, clear pictures of the PCB faces.
Onlyclassab, I don't think the service manual is available publicly, but if I'm wrong, I would be grateful to know; you'll have to debug from the PCB.
In my unit, the 15V supplies originate from Q13 & Q14 which are likely to be regulated somehow from zener diodes. You'll have to sketch out the PCB traces around here to see what to test. It seems strange you've lost both + and - rails, you need to re-check this.
I haven't needed to work on my input/filter board and I have no wish to disassemble the unit unnecessarily. If your 'low' input is working, then it's likely only a relatively isolated part of the pre-amp circuit is suspect. If you're going to disassemble the unit for testing/repairs, then you could try posting very crisp, clear pictures of the PCB faces.
Richard_James, I think there has justifiably been a lot of frustration expressed about the unreliability of some of these expensive REL sub-woofers, but their working performance is widely respected. As a commercial business they have been very generous in confirming the fix you queried, and seem to have been very cooperative with various technical enquiries from other enthusiasts also.
If you wish to edit your post to the fault you are experiencing, it's possible someone may be able to point you in the direction of a fix.
If you wish to edit your post to the fault you are experiencing, it's possible someone may be able to point you in the direction of a fix.
Update:- R8 hasn't failed again as I suspected (post 24/06/2016); therefore, 3 Watts is adequate. However it does still get rather hot, so perhaps further up-rating to 5W may help this component dissipate heat better.
The crackling sounds on my unit this time is being caused by the mains rocker switch, I presume sparking, possibly due to dirty contacts or poor connections. Unplugging the unit and working the mains switch on and off vigorously for a short while seems to provide at least a temporary fix and, more importantly, confirmation of the fault!
So, there appear to be two causes of crackling on these units. It's worth checking the mains switch before changing components, though it's highly likely that at least R8 will need replacing at some point anyway, up-rated from the original 2 Watts.
The crackling sounds on my unit this time is being caused by the mains rocker switch, I presume sparking, possibly due to dirty contacts or poor connections. Unplugging the unit and working the mains switch on and off vigorously for a short while seems to provide at least a temporary fix and, more importantly, confirmation of the fault!
So, there appear to be two causes of crackling on these units. It's worth checking the mains switch before changing components, though it's highly likely that at least R8 will need replacing at some point anyway, up-rated from the original 2 Watts.
It's all fixed and sold. I Don't Have patience For euro garbage That people Pay huge premium for.. AND Get bundle Of problem just Because rel wanted to save 3$/sub. U are saying rel has been generous?) Very funny attitude..yea.. there are other brands.. hsu. Well done svs.
New guys basically . Much better than that 'regarded'rel for which u need to pay 10 times more than its worth
New guys basically . Much better than that 'regarded'rel for which u need to pay 10 times more than its worth
Hm.. it's a very easy project. 10 min per sub max. Ideal amp to learn diy. M sure ull find someone on forum in CA
Vince, Richard_James is quite correct. If you're looking to fix the 'crackling' problem, it would be easy and cheap to buy a 15 watt soldering iron with a 2 or 3mm tip, Antex seem very good, a length of leaded solder and flux, and do a little practice on some spare wires, circuit boards or even paper-clips! If you can't find soldering advice locally, ask back here. Semi-conductors are a bit more tricky, because they mustn't be over-heated, and you need to be sure about the correct connections.
I'd recommend initially just replacing the R8 resistor with a 3 watt, still at 12K ohm and leave the original transistors, then attend to the mains rocker switch as previously posted. I think this might be all you need to achieve a good fix.
Okay I am going to need help, I believe my amp is acting up. I took the woofer out and the amp out. I tested the woofer using my speaker amp and it sounded normal, and I used the amp to power my speakers and it produce the problem.
Where to I start to diagnose the problem and what needs to be replaced.
Where to I start to diagnose the problem and what needs to be replaced.
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.
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.
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.
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.
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.
Agdrago, sorry for the late reply, I find diyaudio isn't very reliable at notifying when someone has posted questions or comments.
Why do you want to replace the 6800uf caps? What are you hoping to achieve?
If you're not planning to replace the transistors, R8 should remain at 12K and the recommended power is 3 watts rather than the original 2 watts. It would be a good idea to mount it well clear of the PCB to assist cooling. I don't think anyone has had to uprate to 5 watts out of necessity.
Do check the mains switch fix before assuming you need component changes. If R8 is degraded, you are likely to see signs of burning or cracking of the component.
Why do you want to replace the 6800uf caps? What are you hoping to achieve?
If you're not planning to replace the transistors, R8 should remain at 12K and the recommended power is 3 watts rather than the original 2 watts. It would be a good idea to mount it well clear of the PCB to assist cooling. I don't think anyone has had to uprate to 5 watts out of necessity.
Do check the mains switch fix before assuming you need component changes. If R8 is degraded, you are likely to see signs of burning or cracking of the component.
Last edited:
Hi,
R8 is definitely showing signs of overheating. 5 watts was easier to source than 3 watts. Where have you seen an appropriate 3-watt wound wire resistor can be sourced?
The switch flickers when on, and when switched off the sounds fades and sizzles. It was my understanding that this should not happen and that the switch and caps could have contributed to the behavior. Any idea where a comparable switch can be sourced?
The sub is quiet and seems to be operating fine otherwise.
R8 is definitely showing signs of overheating. 5 watts was easier to source than 3 watts. Where have you seen an appropriate 3-watt wound wire resistor can be sourced?
The switch flickers when on, and when switched off the sounds fades and sizzles. It was my understanding that this should not happen and that the switch and caps could have contributed to the behavior. Any idea where a comparable switch can be sourced?
The sub is quiet and seems to be operating fine otherwise.
I replaced the R8 resistor with a 12K ohm 3w resistor mounted appropriately high off the circuit board. The flubby-ness of the sub is now gone, but popping on start-up and shut down is enhanced.
The pops are not insanely loud but are alarming. They happen immediately when turning the amp on and 5 seconds after switching the amp off. I am not sure if this is normal.
Any idea of what is likely to be the culprit?
The pops are not insanely loud but are alarming. They happen immediately when turning the amp on and 5 seconds after switching the amp off. I am not sure if this is normal.
Any idea of what is likely to be the culprit?
Agdrago,
I wouldn't recommend a wire wound R8. It will be in the signal path to Q4 and I'd guess the inductance it would cause might be problematic to signal quality and amp performance. I believe metal film would be best, if available, otherwise carbon.
The switch flickering will just be the neon bulb. If you've still got the green one, it is likely to be failing. Otherwise, its possible you can disassemble the switch rocker cover and attach its leads better. I seem to remember they are just clipped into contacts. I replaced my neon with ordinary orange which will last indefinitely, but it doesn't look as funky as the original green. Whilst you're in there, clean the mains switch contacts (pull the mains lead first!); it'll be more thorough than just working the switch up and down vigourously.
If cleaning the switch contacts doesn't help, R8 should fix crackling. I don't think there should be any need to replace the supply capacitors unless you know them to be faulty.
I wouldn't recommend a wire wound R8. It will be in the signal path to Q4 and I'd guess the inductance it would cause might be problematic to signal quality and amp performance. I believe metal film would be best, if available, otherwise carbon.
The switch flickering will just be the neon bulb. If you've still got the green one, it is likely to be failing. Otherwise, its possible you can disassemble the switch rocker cover and attach its leads better. I seem to remember they are just clipped into contacts. I replaced my neon with ordinary orange which will last indefinitely, but it doesn't look as funky as the original green. Whilst you're in there, clean the mains switch contacts (pull the mains lead first!); it'll be more thorough than just working the switch up and down vigourously.
If cleaning the switch contacts doesn't help, R8 should fix crackling. I don't think there should be any need to replace the supply capacitors unless you know them to be faulty.
Last edited:
Regarding popping, my sub makes a substantial pop at start up; there is no 'soft start' or speaker relay installed, so I would expect this from the energising of the supply rails.
Variously I have a few quiet pops at shut down. The amp is DC coupled, which means that there are no decoupling capacitors in the signal path to block DC from the output stage and speaker. This is better for the signal quality, and especially for the low frequencies. At switch-off, the rails lose their potential by draining the reservoir caps, probably unevenly, and the regulated supply is still trying to keep the (quiescent) output stable at close to 0 volts. The pops are the irregularities in the collapsing supply potential causing DC fluctuation in the output stage. This is normal, but I couldn't say what might make the pops more or less prominent.
If you’re very particular, next time you’re inside the unit, disconnect the unit’s input and turn down the volume. After a few minutes, with the speaker disconnected, the voltage on the output rail (where the red speaker lead was) should be close to 0vdc (using the 300mV DC range). Mine measures 0.039vdc. 0.1vdc would be a bit high. A low value indicates that the output rail is being neatly centred by two well-matched transistors in the differential amplifier at the input. An over-high value would merit the replacement of the mis-matched input transistors. It is the fluctuation on this rail which pops the speaker, so re-scale your meter above 300mV before switching off.
I'm a rank amateur, if anyone can provide further information, clarification or correction, please do.
Variously I have a few quiet pops at shut down. The amp is DC coupled, which means that there are no decoupling capacitors in the signal path to block DC from the output stage and speaker. This is better for the signal quality, and especially for the low frequencies. At switch-off, the rails lose their potential by draining the reservoir caps, probably unevenly, and the regulated supply is still trying to keep the (quiescent) output stable at close to 0 volts. The pops are the irregularities in the collapsing supply potential causing DC fluctuation in the output stage. This is normal, but I couldn't say what might make the pops more or less prominent.
If you’re very particular, next time you’re inside the unit, disconnect the unit’s input and turn down the volume. After a few minutes, with the speaker disconnected, the voltage on the output rail (where the red speaker lead was) should be close to 0vdc (using the 300mV DC range). Mine measures 0.039vdc. 0.1vdc would be a bit high. A low value indicates that the output rail is being neatly centred by two well-matched transistors in the differential amplifier at the input. An over-high value would merit the replacement of the mis-matched input transistors. It is the fluctuation on this rail which pops the speaker, so re-scale your meter above 300mV before switching off.
I'm a rank amateur, if anyone can provide further information, clarification or correction, please do.
Last edited: