Hi, my name is Julian Robinson, I'm a fairly recently retired professional viola player (39 years with the CBSO) from Birmingham UK. I have always had an interest in Hi Fi from a teenager, now I have more time to pursue it. Current set up -
Rega RP3, Goldring 1042, various Quad amps and an FM2, Quad 57's and 63's plus Cambridge Audio CXN and CXC and lots of other bits and pieces.
I have a Goldring GL75 which I'm hoping to rebuild, I've signed up to "Lenco Heaven" for that but I also have a pair of Monitor Audio MA4's which I've owned since the early eighties. I've found a place to rebuild the bass/midrange units
AudioLoudspeakers
and the tweeters seem fine but I'm guessing the crossovers would benefit from new caps. My question therefore, is - does anyone have a circuit diagram? I don't own a capacitance meter and I dont really want to spend £100 + on an accurate one which I won't use much. I could reverse engineer the circuit but the capacitor values are not all readable anymore.
Many thanks in advance,
Julian
Rega RP3, Goldring 1042, various Quad amps and an FM2, Quad 57's and 63's plus Cambridge Audio CXN and CXC and lots of other bits and pieces.
I have a Goldring GL75 which I'm hoping to rebuild, I've signed up to "Lenco Heaven" for that but I also have a pair of Monitor Audio MA4's which I've owned since the early eighties. I've found a place to rebuild the bass/midrange units
AudioLoudspeakers
and the tweeters seem fine but I'm guessing the crossovers would benefit from new caps. My question therefore, is - does anyone have a circuit diagram? I don't own a capacitance meter and I dont really want to spend £100 + on an accurate one which I won't use much. I could reverse engineer the circuit but the capacitor values are not all readable anymore.
Many thanks in advance,
Julian
Hi Julian and welcome!
Apparently there are two versions of the MA4 speaker. One of them uses the same crossover as the MA5 and MA7 models.
You can confirm which crossover you have by looking at the back side of the board to see if the markings MA5 and MA7 are present.
The MA4 shown in the attachment is fitted with the MA5/MA7 board.
Apparently there are two versions of the MA4 speaker. One of them uses the same crossover as the MA5 and MA7 models.
You can confirm which crossover you have by looking at the back side of the board to see if the markings MA5 and MA7 are present.
The MA4 shown in the attachment is fitted with the MA5/MA7 board.
Attachments
P.S. In order to ensure responses to your question, you would be advised to repost it in the Loudspeakers/Multi-Way section of the forum.
Researching further, I discover that the Series II version used a crossover board which was specific to the MA4.
The Series I version used a board common to the MA4, MA5 and MA7.
The crossover experts over on the Multi-Way forum will no doubt furnish you with the correct schematic provided you can identify which version you have.
The Series I version used a board common to the MA4, MA5 and MA7.
The crossover experts over on the Multi-Way forum will no doubt furnish you with the correct schematic provided you can identify which version you have.
Thanks for the advice, I'll investigate further!
Thanks for the advice, I'll investigate further!
Thanks for the advice, I'll investigate further!
Not sure to what you refer Tim.
The MA4 shown in my earlier attachment sports an Isophon tweeter. Monitor Audio used this square version in the Series I model.
The Series II model has an HD series Audax tweeter with a round faceplate.
Awaiting confirmation from Juian as to which model he owns.
I have attached a photo of the MA4 Series II this time.
Attachments
Attached is a photo of the MA4 Series II crossover board.
The capacitor values (with modern equivalents in parenthesis) are as follows:
15uF (15uF); 4.7uF (4.7uF); 7uF (6.8uF) and 8uF (8.2uF).
Monacor MKP Polypropylene Capacitors
The capacitor values (with modern equivalents in parenthesis) are as follows:
15uF (15uF); 4.7uF (4.7uF); 7uF (6.8uF) and 8uF (8.2uF).
Monacor MKP Polypropylene Capacitors
Attachments
Sorry Galu, my imagination ran away while I was thinking about a squared-off version of Focal's smaller Kevlar-coned T90.
Is the woofer an Audax?
Attachments
Pictures
Hi, my pair are like the ones in your first picture with the round yellow tweeters on a square plate.
Hi, my pair are like the ones in your first picture with the round yellow tweeters on a square plate.
Thanks for the reply. So you have a MA4 Series 1 and I hope you are now able to replace those original ELCAP capacitors which may have deteriorated significantly by now.
Since the ELCAP capacitors were bipolar electrolytics, you may wish to substitute them with modern bipolar electrolytics which should restore the original sound balance of the speakers. Look again to Wilmslow audio for these: Mundorf Electrolytic ECap Capacitors
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