But I thought each channel needs positive and negative feeds.
My power suppy doesn't have a negative output. That was why I needed to use 2 for the 2 channels.
Cool.
Srinath.
My power suppy doesn't have a negative output. That was why I needed to use 2 for the 2 channels.
Cool.
Srinath.
more ways to rome....
Hi,
The sport is of coarse with little or no money to produce the best hifi (sounding) or high-end power amp.
I like that too!
With what you have " on the shelf" is ALWAYS an option. There is no good or bad ,,,,,it's what you decide/like.
Hi,
The sport is of coarse with little or no money to produce the best hifi (sounding) or high-end power amp.
I like that too!
With what you have " on the shelf" is ALWAYS an option. There is no good or bad ,,,,,it's what you decide/like.
I could open the power supply and see if the transformer has a - and + tap that they only use 1 of and if they do I may just use 1 transformer for the whole amp. the power supply is capable of 1300 watts, something like 27 amp at 42vdc. I am powering a measly 700. Well I'll open up and see.
Thanks.
Srinath.
Thanks.
Srinath.
L20 needs amperes
Hi,
350 watt in 4 ohm meens amperes needed. i bought 2x antek inc 500VA toroidal
24 volt and 21,9 ampere per toroidal. 2x AS2442 parallel use.
Antek - Your reliable source of transformers, power supplies, and more.
The L20 uses max. 20 ampere per channel. So your transformator is more than capable. It meens control over the speaker. it will sound better and more precise. (read; more control)
Hi,
350 watt in 4 ohm meens amperes needed. i bought 2x antek inc 500VA toroidal
24 volt and 21,9 ampere per toroidal. 2x AS2442 parallel use.
Antek - Your reliable source of transformers, power supplies, and more.
The L20 uses max. 20 ampere per channel. So your transformator is more than capable. It meens control over the speaker. it will sound better and more precise. (read; more control)
You used 24 volt trafo, that would be just about 42vdc after you rectify it.
I am doing 42vdc power supply, I may open it and check the trafo. I may have a 24 too, though mine isn't a toroid cos I dont have that center bolt that I can see.
Thanks much marcoben.
Cool.
Srinath.
I am doing 42vdc power supply, I may open it and check the trafo. I may have a 24 too, though mine isn't a toroid cos I dont have that center bolt that I can see.
Thanks much marcoben.
Cool.
Srinath.
hallo Srinath
You are right.....mine will be after rectification 24 volt x 1,41= 34 volt ....so a bit lower as you.
Yours is good...mine is good to.
best regards,
Good luck with the building!
Marco🙂
You are right.....mine will be after rectification 24 volt x 1,41= 34 volt ....so a bit lower as you.
Yours is good...mine is good to.
best regards,
Good luck with the building!
Marco🙂
Grrr Multiply by sq root of 2, I for some stupid reason multiplied by sq root of 3 ...
Cool.
Srinath.
Cool.
Srinath.
Check list:
1) Check voltages in power supply and continuity to boards
2) Check continuity from input jacks to board (Screw down terminal boxes can look connected but are not!)
3) Check for continuity from output to speaker terminals
4) Check for continuity in grounds
If you smelled smoke when you plugged it in, you may have had a short in output and a resistor burned up. Look for a blackened resistor on board
1) Check voltages in power supply and continuity to boards
2) Check continuity from input jacks to board (Screw down terminal boxes can look connected but are not!)
3) Check for continuity from output to speaker terminals
4) Check for continuity in grounds
If you smelled smoke when you plugged it in, you may have had a short in output and a resistor burned up. Look for a blackened resistor on board
L20 V9
I have built this amp as two monoblocks and posted elsewhere on diy audio. I had nothing but trouble initially but after buying 2 more boards have finally got the amps working and 99% finished in their cases. They sound outstandingly good and in some ways I prefer them to my 300B reference monoblock amps (60W/ch.). I built them with speaker protection modules as I still don't trust them fully. However I have about 20 hours on them without problems. My problem is I have 73V rails due to my mains voltage being high and wrong selection of toroids. David. 🙂
I have built this amp as two monoblocks and posted elsewhere on diy audio. I had nothing but trouble initially but after buying 2 more boards have finally got the amps working and 99% finished in their cases. They sound outstandingly good and in some ways I prefer them to my 300B reference monoblock amps (60W/ch.). I built them with speaker protection modules as I still don't trust them fully. However I have about 20 hours on them without problems. My problem is I have 73V rails due to my mains voltage being high and wrong selection of toroids. David. 🙂
You are running the L20 amp on 73v dc ? it didn't blow up ?
You mean +73 - 0 - -73 vdc ?
I have a nice +/-57 vdc I would run to this amp when I build it, got too many projects ATM as well as a move etc.
Cool.
Srinath.
You mean +73 - 0 - -73 vdc ?
I have a nice +/-57 vdc I would run to this amp when I build it, got too many projects ATM as well as a move etc.
Cool.
Srinath.
L20 V9
Yes, +/- 73VDC. Actually the rails were +/- 74V last time I measured them. The trouble is I used toroids which would give +/-70VDC with 240VAC input but my mains voltage is usually 251. I had all sorts of problems with my first set of boards but I don't put the problems down to the high DC although it certainly made a mess when the output semiconductors failed several times. I think it was more my layout and fiddling about that caused the initial problems. Anyway, the amps are working now and sound very good, excellent actually. To save the cost of new todoids I may make up some sort of voltage regulator if I can figure out how to. BTW, my power supply electros are only rated to 80VDC so that's another reason to drop the DC volts. Regards, David.
Yes, +/- 73VDC. Actually the rails were +/- 74V last time I measured them. The trouble is I used toroids which would give +/-70VDC with 240VAC input but my mains voltage is usually 251. I had all sorts of problems with my first set of boards but I don't put the problems down to the high DC although it certainly made a mess when the output semiconductors failed several times. I think it was more my layout and fiddling about that caused the initial problems. Anyway, the amps are working now and sound very good, excellent actually. To save the cost of new todoids I may make up some sort of voltage regulator if I can figure out how to. BTW, my power supply electros are only rated to 80VDC so that's another reason to drop the DC volts. Regards, David.
L20
Hi,
You are on the edge of blowing up. It shows how easy an L20 amp can handle various DC voltages.
specs:
Input Voltage Range: DC±10V - ±70V
I use 24 volt AC ,VDC 33 , 400watt toroidals. 24 ampere per channel.
sound is fantastic.
best regards,
Marco
Hi,
You are on the edge of blowing up. It shows how easy an L20 amp can handle various DC voltages.
specs:
Input Voltage Range: DC±10V - ±70V
I use 24 volt AC ,VDC 33 , 400watt toroidals. 24 ampere per channel.
sound is fantastic.
best regards,
Marco
no point in 400VA transformer pr ch when your running +/-33VDC. you have about 60W at 8ohm. and around 110W at 4ohm. and it can not deliver 24A pr ch. 400/48=8.33A.
Last edited:
I have a +/-57 vdc and 500va chassis I am planning to put it into.
I am not sure what its ampere capacity is - I want to guess its around 6-7 amp. The fuse in that chassis was 6.3 amp.
What would this amp deliver in terms of watts into 8 and 4 ohm loads.
Cool.
Srinath.
I am not sure what its ampere capacity is - I want to guess its around 6-7 amp. The fuse in that chassis was 6.3 amp.
What would this amp deliver in terms of watts into 8 and 4 ohm loads.
Cool.
Srinath.
2*42V transformer? if so. it's 5.95A pr sec.
+/-57V will give you around 170W at 8ohm and around 320W at 4ohm.
+/-57V will give you around 170W at 8ohm and around 320W at 4ohm.
Ha I figured out what you did.
OK lets see if my physics is right.
57v dc is about 42 v ac in the transformer. 42 X 1.4142 = 57.
Max 6.3 amp is for that 42v.
OK so I'm lost. What is the math.
Cool.
Srinath.
OK lets see if my physics is right.
57v dc is about 42 v ac in the transformer. 42 X 1.4142 = 57.
Max 6.3 amp is for that 42v.
OK so I'm lost. What is the math.
Cool.
Srinath.
Audio power - Wikipedia, the free encyclopedia
Undertanding Power Amplifier Power Ratings
here is something to read🙂
Undertanding Power Amplifier Power Ratings
here is something to read🙂
power
hi audiosan,
you are RIGHT!
my toroidals are 400 watt and can deliver max 24Ampere per channel.
Sorry for confusion.
best regards,
marco
hi audiosan,
you are RIGHT!
my toroidals are 400 watt and can deliver max 24Ampere per channel.
Sorry for confusion.
best regards,
marco
70v then
OK I have a 63 v dc chassis. It is 500va I believe.
What will that output be.
Thanks,
Srinath.
OK I have a 63 v dc chassis. It is 500va I believe.
What will that output be.
Thanks,
Srinath.
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