Hello
Sorry for my English level because I live in France !😉
I have an amp REGA Mira 3 that is broken.
The 2 fuses (2A) at the power supply input blow (fuses like small resistance not easy to find as a spare and to replace) but the problem is not there.
I am looking for the schematic to fix it.
Each time the power is switched on, the fuses immediately blow. So there is an immediate short circuit (power transistor in shortcut ? )
What is strange is that the problem suddenly happened overnight without giving any sign of problem previously
Thank you for your helping
Regards
Stephane
Sorry for my English level because I live in France !😉
I have an amp REGA Mira 3 that is broken.
The 2 fuses (2A) at the power supply input blow (fuses like small resistance not easy to find as a spare and to replace) but the problem is not there.
I am looking for the schematic to fix it.
Each time the power is switched on, the fuses immediately blow. So there is an immediate short circuit (power transistor in shortcut ? )
What is strange is that the problem suddenly happened overnight without giving any sign of problem previously
Thank you for your helping
Regards
Stephane
Going by the last thread on this in 2012 there weren't very many compliments flying on your amplifier -- quote --"more like a headphone amplifier " and "power supply capacitors "under size " .
They didn't get a schematic then but according to REGA its got an output short circuit protection circuit which is designed to protect the speakers in case of output device failure .
Now IF --- that works then it would point to a power supply problem .
I know its a BIG IF but in this case I would check out the power supply capacitors and rectifier for faults first then move onto the "blown " ?? output devices .
On further checking REGA wont supply a schematic as somebody else had a fault but he found it was a blown output power transistor which might tie up with the comment- looks more like a headphone amp circuit.
They didn't get a schematic then but according to REGA its got an output short circuit protection circuit which is designed to protect the speakers in case of output device failure .
Now IF --- that works then it would point to a power supply problem .
I know its a BIG IF but in this case I would check out the power supply capacitors and rectifier for faults first then move onto the "blown " ?? output devices .
On further checking REGA wont supply a schematic as somebody else had a fault but he found it was a blown output power transistor which might tie up with the comment- looks more like a headphone amp circuit.
Instead of guesswork : schematics.
Note: all the Rega amps in wide case are the same,
don't be confused by "Mira 2000" in the drawing.
Note: all the Rega amps in wide case are the same,
don't be confused by "Mira 2000" in the drawing.
Thank you to As-Audio for schematics.
As I told you, the problem suddenly arose. No visual defect (caps blow, trace of heat or burn .....)
I forgot to specify that the control part (indicator light, selector, works and lights up!
I also hear the protection relay which engages. The problem therefore comes from the power part.
I hope I can solve the problem with the schematic
As I told you, the problem suddenly arose. No visual defect (caps blow, trace of heat or burn .....)
I forgot to specify that the control part (indicator light, selector, works and lights up!
I also hear the protection relay which engages. The problem therefore comes from the power part.
I hope I can solve the problem with the schematic
"Guess work " I said check the power supply --and you are saying ---check Br1 + C1.. C4 and they are ----?? . If I am "guessing " then so are you .
Its called --tracing a fault ---without a crystal ball .
Its called --tracing a fault ---without a crystal ball .
I speculated on the back of previous DIY Audio users on this subject as I posted --the thread is in 2012 so if you are criticizing me for that then you are obviously criticizing them and other owners elsewhere .
Yes I will start by checking the capacitors (the diode bridge is already done => OK). It's harder to unsolder, but they look good even though they're not audiophile components. That said, cap problems are quite common on old amps and especially NADs, and there it was enough to look closely to see that they had often blowed at the terminals, which is not the case here
How do the leds work if You press power and the fuses blow ? Work for 1 second ?
Reading the schematic above, fuses F1 & F2 on the right top side are after the main rails and powering the pre-amp supply regs (middle top). I would check that bridge and those capacitors. Do You have Voltage from the +- 15 V supplies ?
Hello
Just for your information,I found the breakdown.
The problem arose from one of the 4 caps which was shorted.( C3 no apparent defect !)
It must be said that the caps of this amp are of poor quality (Samwha brand) including on the main power supply !
I will do a total recaps to replace all of them and replace famous brands (Panasonic, Nichicon, Elna ..)
Thank you again for the schematics
Regards
Just for your information,I found the breakdown.
The problem arose from one of the 4 caps which was shorted.( C3 no apparent defect !)
It must be said that the caps of this amp are of poor quality (Samwha brand) including on the main power supply !
I will do a total recaps to replace all of them and replace famous brands (Panasonic, Nichicon, Elna ..)
Thank you again for the schematics
Regards
It's unusual to to find a shorted capacitor in a domestic amplifier but good work in locating that fault.
Actually Samwha branded caps have a good reputation among pro. repairers of general audio and home entertainment gear. I suspect it is the un-cool sounding brand name that deters hi-fi fans and amateur repairers from what is really no worse and sometimes better than other, well known brands of caps.
Bear in mind that caps come in various grades and audio amps can require specific qualities like plenty of ripple current rating, hence low ESR ratings to perform at their best for their rated working life. Yes, a working life of at least 1,500 hours at maximum ratings would be a minimum for quality audio gear. As you might expect, those qualities directly affect the selling cost in what is a very competitive market, both for the components and finished amp.
Actually Samwha branded caps have a good reputation among pro. repairers of general audio and home entertainment gear. I suspect it is the un-cool sounding brand name that deters hi-fi fans and amateur repairers from what is really no worse and sometimes better than other, well known brands of caps.
Bear in mind that caps come in various grades and audio amps can require specific qualities like plenty of ripple current rating, hence low ESR ratings to perform at their best for their rated working life. Yes, a working life of at least 1,500 hours at maximum ratings would be a minimum for quality audio gear. As you might expect, those qualities directly affect the selling cost in what is a very competitive market, both for the components and finished amp.
Regarding the cost of sales, I completely agree with you! For several decades now, almost all Hifi manufacturers have sought to maximize their profit by saving on component costs.
The easiest for them is to choose cheaper capacitors with low cost brands, or low characteristics (temperature, ESR, life time, ......)
I have seen this fact on many audiophile brands, such as ARCAM, NAD, and now REGA. Fortunately, it is easy to troubleshoot these devices and increase their performance, by choosing better quality components.
I recently discovered the brand of NOVER capacitor, which is good value for money,
Conversely, I saw that there were "special" audiophile capacitors with, supposedly, exceptional characteristics with a very professional aspect which are expensive and which ultimately are very disappointing to listen to ....
In short, difficult to form an opinion in this jungle ....
Personally, I'm loyal to brands like ELNA, Panasonic, Rubycon, or Nichicon
The easiest for them is to choose cheaper capacitors with low cost brands, or low characteristics (temperature, ESR, life time, ......)
I have seen this fact on many audiophile brands, such as ARCAM, NAD, and now REGA. Fortunately, it is easy to troubleshoot these devices and increase their performance, by choosing better quality components.
I recently discovered the brand of NOVER capacitor, which is good value for money,
Conversely, I saw that there were "special" audiophile capacitors with, supposedly, exceptional characteristics with a very professional aspect which are expensive and which ultimately are very disappointing to listen to ....
In short, difficult to form an opinion in this jungle ....
Personally, I'm loyal to brands like ELNA, Panasonic, Rubycon, or Nichicon
Ah yes, but which grade of these old Japanese brands? You can buy cheaper, genuine Nichicon caps that are no better than other cheap caps and most of their popular grades for class AB amplifiers from 20 or more years ago are now obsolete or if you trust NOS capacitors, you may be able to buy some online at the right price.
Often, I believe that I hear better performance with less well-known cap. brands like Nippon Chemicon, in suitable grades. DIY devotion to certain traditional brands is really about gaining credibility from safe brand associations, like anything we come to trust because either our peers will jump on and criticise anything else, we don't experiment with or know enough about other brand products or they don't meet with some standard, drafting profile, terminal type etc. Some folk believe its the country of origin that matters or some other irrelevance but audio technology does attract all kinds of polarised responses, whatever the topic.
Often, I believe that I hear better performance with less well-known cap. brands like Nippon Chemicon, in suitable grades. DIY devotion to certain traditional brands is really about gaining credibility from safe brand associations, like anything we come to trust because either our peers will jump on and criticise anything else, we don't experiment with or know enough about other brand products or they don't meet with some standard, drafting profile, terminal type etc. Some folk believe its the country of origin that matters or some other irrelevance but audio technology does attract all kinds of polarised responses, whatever the topic.
Personally I like the FC serial from Panasonic or Muse from Nichicon, the LKG serial is even better but expensive !
Yes, Nippon Chemicon are very good capacitors, we could also mention EPCOS also
In short, a lot of choice in this field, so all the more reason to replace low-cost capacitors or no name with reputable brands
Yes, Nippon Chemicon are very good capacitors, we could also mention EPCOS also
In short, a lot of choice in this field, so all the more reason to replace low-cost capacitors or no name with reputable brands