Francec:
You can absolutely run the amplifier in that arrangement, and it should work very well set up like that. It would probably be best to run each as single ended input and just use a balanced input with the positive phase running one amp, and the negative phase running the other. Would that be your plan? If so, your even order harmonics should be reduced somewhat thanks to the differential arrangement. If you ran both legs of the bridge off the same PSU, your PSRR would also increase. Overall, it would definitely be a benefit.
Cheers,
Owen
You can absolutely run the amplifier in that arrangement, and it should work very well set up like that. It would probably be best to run each as single ended input and just use a balanced input with the positive phase running one amp, and the negative phase running the other. Would that be your plan? If so, your even order harmonics should be reduced somewhat thanks to the differential arrangement. If you ran both legs of the bridge off the same PSU, your PSRR would also increase. Overall, it would definitely be a benefit.
Cheers,
Owen
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4 ohms would be fine as well since each individual amp won't have a problem with a 2 ohm load, and the peak current through the device won't exceed 20A.
The key is to not go overboard with your rails if you run that arrangement. You double the voltage swing capability of a single amp, and that doubles the current delivered to the load which quadruples the power. If you run each amp at its maximum SE power envelope, then bridge two amps into the same load, you'll be exceeding the power envelope by a factor of two for each amp which is not acceptable.
It's also easy to run into the current limitations of the mosfets themselves. it would be advisable to never let the peak current exceed 20A for any individual device, and even that is really pushing it. In that case, with a 4 ohm load driven by a bridged pair, you should keep the rails at a maximum of 35V to keep the peak current at around 17.5 amps. That would give you about 600 watts of power, and I'm assuming each half of the bridge has a sufficient amount of heatsinking to deal with that much dissipation.
I've updated the worksheet to include bridged options. Pleas find attached.
Regards,
Owen
The key is to not go overboard with your rails if you run that arrangement. You double the voltage swing capability of a single amp, and that doubles the current delivered to the load which quadruples the power. If you run each amp at its maximum SE power envelope, then bridge two amps into the same load, you'll be exceeding the power envelope by a factor of two for each amp which is not acceptable.
It's also easy to run into the current limitations of the mosfets themselves. it would be advisable to never let the peak current exceed 20A for any individual device, and even that is really pushing it. In that case, with a 4 ohm load driven by a bridged pair, you should keep the rails at a maximum of 35V to keep the peak current at around 17.5 amps. That would give you about 600 watts of power, and I'm assuming each half of the bridge has a sufficient amount of heatsinking to deal with that much dissipation.
I've updated the worksheet to include bridged options. Pleas find attached.
Regards,
Owen
well lets just say that i don't usually associate irony with the USA comedic repertoire
Bill,
I think we're all just keeping ourselves entertained until Owen comes through with some PCB pics
but its mostly this
all work and no play makes HYPERTUNE a very dull boy? looks familiar
i'm actually a bit annoyed that i didn't see this coming, but i had a ermmm 'copy' of maya unlimited 8 that I've been using on my g5 for the last couple of years; with all the extra physics packages etc. but i recently bought a new mac and its not supported on Lion =( i should have remembered that. i'm good with all my usual design suspects as they are all legit and up to date, but not only do i not make money from modelling i don't use it enough to justify the coin. pissed off, i was actually pretty keen to see how the AVX vector engine handled it. looks like i might have to go back to the basic version and bite the bullet
do you know if you can rent/lease seats?
love the grounding set up Owen!!
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While output disipation and the like are still in recent memory....
Owen.
Can I get extra transistors for the amps I ordered?
A compliment of at least four per channel is a little more like long term safety margin I'm interested in. Extras to do some decent matching would also be an asset. It would allow for a wider output current peak into stranger loads that I work with. Should be doing some electrostatic work in not to long a time. Not the easiest things to drive. And I'm looking at some current amp work for another project.
Owen.
Can I get extra transistors for the amps I ordered?
A compliment of at least four per channel is a little more like long term safety margin I'm interested in. Extras to do some decent matching would also be an asset. It would allow for a wider output current peak into stranger loads that I work with. Should be doing some electrostatic work in not to long a time. Not the easiest things to drive. And I'm looking at some current amp work for another project.
Hi Mark,
No problem at all. I'll add a column to the list for those who just want the Semelab lateral mosfets.
I'm actually getting that order together now, so if everyone who wants transistor above and beyond what is already included in the kits (or if you just bought boards but still want the fets) please post your requests up here so I can get an idea of how many extra parts I'll need.
I'll probably close and lock all the parts orders by the end of next week, so I'd say people have until then to get their orders in.
Cheers,
Owen
No problem at all. I'll add a column to the list for those who just want the Semelab lateral mosfets.
I'm actually getting that order together now, so if everyone who wants transistor above and beyond what is already included in the kits (or if you just bought boards but still want the fets) please post your requests up here so I can get an idea of how many extra parts I'll need.
I'll probably close and lock all the parts orders by the end of next week, so I'd say people have until then to get their orders in.
Cheers,
Owen
Hi again.
What are your recommendations for the power supply for the LME? Assuming that Cristi makes a nice supply is it still a good idea to have an additional separate linear supply for the LME, and is one supply enough for 2 channels?
Most importantly is it still possible to sign up for more PSU boards and components?
If i'm not mistaken this is my order so far:
5 Amp PCB
3 Amp kits
1 BAL-SE PCB
1 BAL-BAL PCB
1 PSU PCB
I would like to add another 3 transistor pairs for matching and safety margin if i break one...
What are your recommendations for the power supply for the LME? Assuming that Cristi makes a nice supply is it still a good idea to have an additional separate linear supply for the LME, and is one supply enough for 2 channels?
Most importantly is it still possible to sign up for more PSU boards and components?
If i'm not mistaken this is my order so far:
5 Amp PCB
3 Amp kits
1 BAL-SE PCB
1 BAL-BAL PCB
1 PSU PCB
I would like to add another 3 transistor pairs for matching and safety margin if i break one...
@ QRikard:
i really wish people would read the thread, wouldn't even need to read the whole thread for that question because its asked on almost every page. yes there is a pcb for a regulated front end and yes its recommended. check out opc's 'the wire' headphone amp thread GB, the psu for this is easily repurposed for this amp.
i really wish people would read the thread, wouldn't even need to read the whole thread for that question because its asked on almost every page. yes there is a pcb for a regulated front end and yes its recommended. check out opc's 'the wire' headphone amp thread GB, the psu for this is easily repurposed for this amp.
@ qusp
I have read the thread (some time ago now so i have probably forgotten some parts). Using a regulated front end is given but Cristis SMPS should already have a linear regulator for the front end, so maybe my question was unclear.
What i meant was if another regulated supply has any significant improvement over just using the one in the SMPS supply. I can't remember this question being answered before...
I have read the thread (some time ago now so i have probably forgotten some parts). Using a regulated front end is given but Cristis SMPS should already have a linear regulator for the front end, so maybe my question was unclear.
What i meant was if another regulated supply has any significant improvement over just using the one in the SMPS supply. I can't remember this question being answered before...
Then i apologize, must have missed/forgotten that part, i do recognize some of it now when you say it...
Owen: If there is still boards and kits left from the additional panels, please sign me up for another 3 PSU boards + kits. With high voltage components if possible so it works with the amp.
Owen: If there is still boards and kits left from the additional panels, please sign me up for another 3 PSU boards + kits. With high voltage components if possible so it works with the amp.