Hi all, just a quickie!😀
Would it be possible to take a 4 channel amp and convert it to a 1 channel amp? Don't get me wrong, I'm not looking for more power. I have a Maystar 4 channel jobby. I've had it for years and its never failed even though its had a bit of Pepsi spilt down the fan vent,OOPS
it didn't die
, and I'm running 2 of the channels in bridge mode for my sub. I can't afford to go and buy a new amp, but, am I not wasting unused amperes in the switch mode, because the other 2 channels aren't being used, plus maybe it would sound better if I just had a pair of transistors driving my woofer?
Or maybe a parallel pair?
With reference to
http://www.diyaudio.com/forums/showthread.php?s=&threadid=109906
post no3, djQUAN has a psu, in which he says he drew a line across the board and cut it, (obviously in the right place). I've looked at the board and at first glance, there's more than just +/- and Gnd tracks, djQUAN if you read this, how the heck did you decide what/where to cut?😕
It says 4 x 100 watts on the sticker , but by time you realise this, its probably BS, what sort of sensible power could I expect if I could pull it off? I'm only driving a 10inch in a wedge 50 quid special. So maybe 75wr.m.s. overall. I could do with something meaty to do, for the winter months. What do you think?
Cheers
iUSERTLO72p🙂
Would it be possible to take a 4 channel amp and convert it to a 1 channel amp? Don't get me wrong, I'm not looking for more power. I have a Maystar 4 channel jobby. I've had it for years and its never failed even though its had a bit of Pepsi spilt down the fan vent,OOPS
it didn't die , and I'm running 2 of the channels in bridge mode for my sub. I can't afford to go and buy a new amp, but, am I not wasting unused amperes in the switch mode, because the other 2 channels aren't being used, plus maybe it would sound better if I just had a pair of transistors driving my woofer?Or maybe a parallel pair?
With reference to
http://www.diyaudio.com/forums/showthread.php?s=&threadid=109906
post no3, djQUAN has a psu, in which he says he drew a line across the board and cut it, (obviously in the right place). I've looked at the board and at first glance, there's more than just +/- and Gnd tracks, djQUAN if you read this, how the heck did you decide what/where to cut?😕
It says 4 x 100 watts on the sticker , but by time you realise this, its probably BS, what sort of sensible power could I expect if I could pull it off? I'm only driving a 10inch in a wedge 50 quid special. So maybe 75wr.m.s. overall. I could do with something meaty to do, for the winter months. What do you think?
Cheers
iUSERTLO72p🙂
Just buy one dual voice coil (4 ohm per coil) subwoofer. Bridge two channels on one woofer coil, and bridge the other two channels on the other woofer coil. No wasted power 🙂
Just be sure to adjust both gains and crossover frequencies exactly the same or it won't be as efficient. Someone here can surely tell you how to match the gains. I'm not going to wear my fingers out explaining how to, someone else will surely have a better way anyway.
Just be sure to adjust both gains and crossover frequencies exactly the same or it won't be as efficient. Someone here can surely tell you how to match the gains. I'm not going to wear my fingers out explaining how to, someone else will surely have a better way anyway.
Yes, thats one way but...
This suggests that I'm broke😀 , also the idea is to maybe use one of Rod Elliotts projects, and maybe learn something. Okay some people might not go for having quality bass in there motor, but I like it.
Cheers for the response, If I had the readies, I'd go that route. Although my amp has 2 filters, 2 channels on high pass and 2 on lowpass. Or all 4 flat.
Cheers
iUSERTLO72p🙂
This suggests that I'm broke😀 , also the idea is to maybe use one of Rod Elliotts projects, and maybe learn something. Okay some people might not go for having quality bass in there motor, but I like it.
Cheers for the response, If I had the readies, I'd go that route. Although my amp has 2 filters, 2 channels on high pass and 2 on lowpass. Or all 4 flat.
Cheers
iUSERTLO72p🙂
there are actually two V+, two V- and one gnd tracks because it is a dual supply amp. both V+ and V-'s have the same output voltages but are independent of each other because they have separate power transformers, rectifiers and output caps.
just look around the circuit and trace the copper running from the output to the rectifiers, inductors and output capacitors and see where you can cut a nearly straight line. just make sure if the powersupply has some feedback path for regulation, don't cut that part. 😉
cutting was done using a dremel type tool and a cutting disc attachment.
you can use only two channels on a 4 channel amp and if it has a single supply (most likely it does but I'm not sure) then using only two channels rather than four is not wasting any power but even better for the PSU since it has extra juice from the unused channels that can be used by the other two.
Re: Yes, thats one way but...
Even if you run all four channels into one mono channel, you're not going to gain any more power output (assuming you keep the same woofer). The current capability of the amp could theretically go up, but since the amp will still be running the same voltage in the power supply, and the woofer impedance is staying the same (because you can't buy a new one, and I'm assuming its a single 4 ohm version since you haven't stated to the contrary) you will be using pretty much the same wattage. The damping will change slightly but the amp's voltage maximum will be the same. That is why I suggested changing the woofer type to require more current from the amp.
😉
iUSERTLO72p said:
Even if you run all four channels into one mono channel, you're not going to gain any more power output (assuming you keep the same woofer). The current capability of the amp could theretically go up, but since the amp will still be running the same voltage in the power supply, and the woofer impedance is staying the same (because you can't buy a new one, and I'm assuming its a single 4 ohm version since you haven't stated to the contrary) you will be using pretty much the same wattage. The damping will change slightly but the amp's voltage maximum will be the same. That is why I suggested changing the woofer type to require more current from the amp.
😉
Hi!
That is true, but P = U x I (20V x 4 x 5A ).
This situation is good for Low impedance speaker<2Ohm.
BTW for vhich car you want to use this amp.
Regards zeoN_Rider
That is true, but P = U x I (20V x 4 x 5A ).
This situation is good for Low impedance speaker<2Ohm.
BTW for vhich car you want to use this amp.
Regards zeoN_Rider
Hello gain
Hello, I just wanted to improve the amp. I assume that using 1x 4 ohm driver, sorry should have said😀 , that I could build a better quality amp. I don't know how the power rating would change. I just wondered if the powersupply could just run one set of transistors/or parallel another pair, to give the same power as 2 channels bridged. I was thinking that the crossover distortion created by the bridge be removed and maybe THD/Damping or whatever goes into making an amp stage perform well.
I don't fancy trying to build a SMPS, seems too complicated. But a new amp stage would be nice.
Many thanks for replying. I was looking at attaching this or similar
http://sound.westhost.com/project3a.htm
What do you think djQUAN?
Cheers
iUSERTLO72p🙂
Hello, I just wanted to improve the amp. I assume that using 1x 4 ohm driver, sorry should have said😀 , that I could build a better quality amp. I don't know how the power rating would change. I just wondered if the powersupply could just run one set of transistors/or parallel another pair, to give the same power as 2 channels bridged. I was thinking that the crossover distortion created by the bridge be removed and maybe THD/Damping or whatever goes into making an amp stage perform well.
I don't fancy trying to build a SMPS, seems too complicated. But a new amp stage would be nice.
Many thanks for replying. I was looking at attaching this or similar
http://sound.westhost.com/project3a.htm
What do you think djQUAN?
Cheers
iUSERTLO72p🙂
I don't think you could squeeze more than about 200 watts off that power supply.
the transformer has a 6T:12T primary to secondary turns so that means about 25V secondary supply voltage.
you're probably getting about 50watts cont x 4 at 4ohms or about 200watts cont x 2 at 4ohms bridged.
I don't think you could change the power output much since it is already maxed out. as for sound quality, you might as well build a new amp from scratch since you would replace many parts or redesign the amplifier section.
I'm not trying to discourage you, just letting you know what you're going to get into. 🙂
the transformer has a 6T:12T primary to secondary turns so that means about 25V secondary supply voltage.
you're probably getting about 50watts cont x 4 at 4ohms or about 200watts cont x 2 at 4ohms bridged.
I don't think you could change the power output much since it is already maxed out. as for sound quality, you might as well build a new amp from scratch since you would replace many parts or redesign the amplifier section.
I'm not trying to discourage you, just letting you know what you're going to get into. 🙂
Thanks djQUAN
Hello again,
Looking at Rods amp, I could run that off of it, at a reduced power output. Would it sound better with his amp???
I can't even slide the bl**dy board out! Those clamps and the heatsink compound must have it locked tight.
I have heard a JBL GTO at the same power sound warm in the bass, where as this sounded thin and dry. Thats why I was curious about being able to do this. I'm assuming the JBL to be a better amp, it was a GTO somthing or other.
Cheers
iUSERTLO72p🙂
Hello again,
Looking at Rods amp, I could run that off of it, at a reduced power output. Would it sound better with his amp???
I can't even slide the bl**dy board out! Those clamps and the heatsink compound must have it locked tight.
I have heard a JBL GTO at the same power sound warm in the bass, where as this sounded thin and dry. Thats why I was curious about being able to do this. I'm assuming the JBL to be a better amp, it was a GTO somthing or other.
Cheers
iUSERTLO72p🙂
you could try and use a separate active crossover. most cheap amps use crappy crossovers which do things that doesn't have anything to do with the markings on the amp. 
run that amp in full range mode then use a good quality active crossover unit. you might hear some improvement.
run that amp in full range mode then use a good quality active crossover unit. you might hear some improvement.
Hi djQUAN
Okay, I'll look for a xover then, maybe a Linkwitz 24db.
The amp reckons Variable18db @45hz bass boost,
hmm yeah right and then each xover does it at 12db, lowpass 30 through 250 hz.
What would a sensible amp have, If I rebuild this stage, how elaborate can I go? What do the best audiophiles use?
Cheers
iUSERTLO72p🙂
Okay, I'll look for a xover then, maybe a Linkwitz 24db.
The amp reckons Variable18db @45hz bass boost,
hmm yeah right and then each xover does it at 12db, lowpass 30 through 250 hz.What would a sensible amp have, If I rebuild this stage, how elaborate can I go? What do the best audiophiles use?
Cheers
iUSERTLO72p🙂
I have made car amps using P3A with great results. 😉 much better than cheap amps.
also, an explanation to the better sounding JBL amp is that it is more expensive and most probably higher power.
also, an explanation to the better sounding JBL amp is that it is more expensive and most probably higher power.
Hi!
This is very small car, like mine ( Renault Twingo ).
I have in the trunk 12" double coil SW. (2x4Ohm.), powered with Pioneer GM 1200.
When I, put in max. HU. I, can't breathe.
Put in parallel in/out and one 15" SW.,you'll never have neighbour any more.
Regards zeoN_Rider
This is very small car, like mine ( Renault Twingo ).
I have in the trunk 12" double coil SW. (2x4Ohm.), powered with Pioneer GM 1200.
When I, put in max. HU. I, can't breathe.
Put in parallel in/out and one 15" SW.,you'll never have neighbour any more.
Regards zeoN_Rider
Hello gain
Hi djQUAN, Would adding a P3A be better than the maystar? Maybe 2 in bridge mode,courtesy of P14 and project 09 front end, to do the filtering.
zeonrider, my neighbour is likely to torch my ride!
Quality only
Cheers
iUSERTLO72p
Hi djQUAN, Would adding a P3A be better than the maystar? Maybe 2 in bridge mode,courtesy of P14 and project 09 front end, to do the filtering.
zeonrider, my neighbour is likely to torch my ride!
Quality only
Cheers
iUSERTLO72p
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