RS have some 20watt 39volt zener diodes, would these be ok? the address is: http://rswww.com/cgi-bin/bv/browse/Module.jsp?BV_SessionID=@@@@0487846058.1045145992@@@@&BV_EngineID=cccdadchhmmmljfcfngcfkmdgkldfhk.0&3222599094=3222599094&catoid=-94636531
RS have some 20watt 39volt zener diodes, would these be ok?
If you use a higher voltage supply then you will need to find some way to drop the extra voltage, or the amp will fry.
Zeners are not really the way to go - the problem here is that any form of voltage dropping ( without going to the trouble of building a switching regulator ) is going to have to dissipate the extra energy as heat. If you are using a 60v rail (for example) and you want to run your amp from a 42v rail , then the extra 18volts needs to be dropped by the regulator.
Suppose your amp draws 3Amps ( approximately the figure for a 60-80W amp ) from each rail at full load, the supply current will be the same for the regulator both before and after regulation , so the regulation device must dissipate:
P=I x V , or 3 x 18 = 54 Watts of heat for each rail.
effectively, for each extra 20v of secondary voltage you are dissipating about twice as much heat from the PSU as you would in the amp itself !!
you can do this, a simple way would be a zener and a pass transistor , but the transistor will get quite hot, and will need very good heatsinking. you can accept this if the voltage drop is quite small or the amp draws little power , but it's not ideal.
There are much better regulation ideas around - I suggest you search this forum - but you will probably end up spending more time and money building a regulator than you will on the amp, and they'll still have to dissipate the same amount!
It's a much , much better idea to match the transformer to the amp requirements if you want to build a simple project. Save the nice regulated PSU for another bigger project.
If you use a higher voltage supply then you will need to find some way to drop the extra voltage, or the amp will fry.
Zeners are not really the way to go - the problem here is that any form of voltage dropping ( without going to the trouble of building a switching regulator ) is going to have to dissipate the extra energy as heat. If you are using a 60v rail (for example) and you want to run your amp from a 42v rail , then the extra 18volts needs to be dropped by the regulator.
Suppose your amp draws 3Amps ( approximately the figure for a 60-80W amp ) from each rail at full load, the supply current will be the same for the regulator both before and after regulation , so the regulation device must dissipate:
P=I x V , or 3 x 18 = 54 Watts of heat for each rail.
effectively, for each extra 20v of secondary voltage you are dissipating about twice as much heat from the PSU as you would in the amp itself !!
you can do this, a simple way would be a zener and a pass transistor , but the transistor will get quite hot, and will need very good heatsinking. you can accept this if the voltage drop is quite small or the amp draws little power , but it's not ideal.
There are much better regulation ideas around - I suggest you search this forum - but you will probably end up spending more time and money building a regulator than you will on the amp, and they'll still have to dissipate the same amount!
It's a much , much better idea to match the transformer to the amp requirements if you want to build a simple project. Save the nice regulated PSU for another bigger project.
I have decided to make Elliot Sound Project's High Quality Audio Preamp (Mk II) (project 88) to go with the power amp i am going to construct. is this a good decision?
i will get the 300VA 25volt transormer for the power amp.
i will get the 300VA 25volt transormer for the power amp.
Yep!
If you can't get the OPA2134 opamp, try the NE5534 😉 😉
But... if you want to connect the High Quality Audio Preamp (Mk II) to a Krell 😱 ... use an opamp better than the OPA2134 😎
If you can't get the OPA2134 opamp, try the NE5534 😉 😉
But... if you want to connect the High Quality Audio Preamp (Mk II) to a Krell 😱 ... use an opamp better than the OPA2134 😎
Krell/reply
Hi Halojoy,
My friend is in the happy circumstance to own a pair of these Krell space heaters. He prefers the VTL 700's to the Krells.
Totally off subject : I have sent you some 5 emails regarding the schematic of the Denesson JC-80 schematic by John Curl. Apparently it escaped your attention. Would you please be so kind to answer my emails??? 😕
🙄 
Hi Halojoy,
My friend is in the happy circumstance to own a pair of these Krell space heaters. He prefers the VTL 700's to the Krells.
Totally off subject : I have sent you some 5 emails regarding the schematic of the Denesson JC-80 schematic by John Curl. Apparently it escaped your attention. Would you please be so kind to answer my emails??? 😕
🙄 
opamp 5532?
Wouldn't he really want the 5532-the dual opamp? That looks pin compatible.
What opamps are better than the opa2134?
Wouldn't he really want the 5532-the dual opamp? That looks pin compatible.
What opamps are better than the opa2134?
Re: opamp 5532?
tests say:
---------
NE5532 is better than OPA2134.
5532 gives better perspective and slightly larger roomspace.
Also a more comfortable feeling in the deep bass,
more distinct, especially with natural bass-guitars.
---------
So my choice is given: The low price NE5534/5532 all the way...
/halo - old and with a hearing below average,
take his listeningtest - with a GIANT LAUGH!
My listeningdwjj said:
tests say:---------
NE5532 is better than OPA2134.
5532 gives better perspective and slightly larger roomspace.
Also a more comfortable feeling in the deep bass,
more distinct, especially with natural bass-guitars.
---------
So my choice is given: The low price NE5534/5532 all the way...
/halo - old and with a hearing below average,
take his listeningtest - with a GIANT LAUGH!
thanks
I hadn't seen that opamp. There are so (SO) many, it's nice to find a decent&cheap one.
It's funny-the software you're using in Sweden comes from the town next to me. Small world!
I hadn't seen that opamp. There are so (SO) many, it's nice to find a decent&cheap one.
It's funny-the software you're using in Sweden comes from the town next to me. Small world!
Re: thanks
this small
those you communicate with are CLOSE to you
distance & lack of communication creates suspicion
and can utimately result in WAR
/halo - helps to make world smaller
diyaudio.com helps us to make the worlddwjj said:
this small
those you communicate with are CLOSE to you
distance & lack of communication creates suspicion
and can utimately result in WAR
/halo - helps to make world smaller
i have found out that my speakers are goodmans, and on the back i says:
goodmans mezzo SL
nom. power input: 60w
max. RMS input:36w
imp:8ohm
sens:7w
what does this mean? are these good speakers?
goodmans mezzo SL
nom. power input: 60w
max. RMS input:36w
imp:8ohm
sens:7w
what does this mean? are these good speakers?
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