Has anyone used the PA05 Operational Amplifier in thier designs?
This amp is amazing, .001% THD @ 200W, .01% THD @ 300W.
http://eportal.apexmicrotech.com/mainsite/products/pages/op_amps/pa05.asp?guid=
I still can not get over these specs:
ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, +VS to –VS 100V
OUTPUT CURRENT, continuous within SOA 30A
POWER DISSIPATION, internal 250W
INPUT VOLTAGE, differential ±20V
OPERATING TEMPERATURE RANGE, case –55 to +125°C
COMMON MODE REJECTION, DC Full temp. range, VCM = ±20V 90 100 * * dB
INPUT NOISE 100KHz BW, RS = 1KΩ 10 * µVrms
GAIN
OPEN LOOP, @ 15Hz Full temperature range, CC = 82pF 94 102 * * dB
GAIN BANDWIDTH PRODUCT RL = 10Ω 3 * MHz
POWER BANDWIDTH RL = 4Ω, VO = 80VP-P, AV = –10 400 * kHz
CC = 82pF, RC = 120Ω
PHASE MARGIN Full temperature range, CC = 470pF 60 * °
OUTPUT
An externally hosted image should be here but it was not working when we last tested it.
This amp is amazing, .001% THD @ 200W, .01% THD @ 300W.
http://eportal.apexmicrotech.com/mainsite/products/pages/op_amps/pa05.asp?guid=
I still can not get over these specs:
ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, +VS to –VS 100V
OUTPUT CURRENT, continuous within SOA 30A
POWER DISSIPATION, internal 250W
INPUT VOLTAGE, differential ±20V
OPERATING TEMPERATURE RANGE, case –55 to +125°C
COMMON MODE REJECTION, DC Full temp. range, VCM = ±20V 90 100 * * dB
INPUT NOISE 100KHz BW, RS = 1KΩ 10 * µVrms
GAIN
OPEN LOOP, @ 15Hz Full temperature range, CC = 82pF 94 102 * * dB
GAIN BANDWIDTH PRODUCT RL = 10Ω 3 * MHz
POWER BANDWIDTH RL = 4Ω, VO = 80VP-P, AV = –10 400 * kHz
CC = 82pF, RC = 120Ω
PHASE MARGIN Full temperature range, CC = 470pF 60 * °
OUTPUT
That is a very nice looking opamp.
I wouldn't be able to fork out the money for that price, however, the idea is definitely worth trying if you can afford it.
That sucker looks like you might need a sophisicated heatsink though.
I'd certainly be interested to see a design incorporating that chip.
One could build an especially simple amplifier with power opamps like that. It would probably be quite reliable and compact. I'm wondering what the sound quality would be like. And also what modes of amplifier operation you could achieve.
I wouldn't be able to fork out the money for that price, however, the idea is definitely worth trying if you can afford it.
That sucker looks like you might need a sophisicated heatsink though.
I'd certainly be interested to see a design incorporating that chip.
One could build an especially simple amplifier with power opamps like that. It would probably be quite reliable and compact. I'm wondering what the sound quality would be like. And also what modes of amplifier operation you could achieve.
APEX has been building high-power chips for at least 12 years. I believe they are mostly used for motor control. I've always been curious how they might work on a subwoofer application as they spec most impressively but have not wanted to be the gweenya-pig either.
Has anyone tried them on audio applications?
speaker
Has anyone tried them on audio applications?
speaker
Pretty interesting what you can get into a small package. A few of observations from the data sheet:
--To get those great THD figures you can't operate it over the 200W level.
--Attention to the power supply is needed since the PSRR at 1kHz and below is OK but not super.
--Heatsinking may be critical as the power rating falls rapidly above ambient. At 76C you only have a 150W amp, at 100C only a 100W amp. If I was trying to make one go, I'd plan on a fan from the start. This pretty much makes it dubious a a plate amp for a sub.
- I would want to study the SOA a bit more; with a 4 ohm speaker or a nominal 8 ohm that has big dips you may have less power than available than first appears. The 30A current figure doesn't mean much when you match it against the voltages you are more likely to require.
-- There is no info on clipping characteristics: clean, soft, ugly. . .?
I'm not nocking it. It would be fun to mess with if they were giving them away for free. It has the both the principal pluses and minuses of any IC amp: it lets you build an amp with few parts but you are limited to what it is. In passing, I wonder if it can be bridged.
--To get those great THD figures you can't operate it over the 200W level.
--Attention to the power supply is needed since the PSRR at 1kHz and below is OK but not super.
--Heatsinking may be critical as the power rating falls rapidly above ambient. At 76C you only have a 150W amp, at 100C only a 100W amp. If I was trying to make one go, I'd plan on a fan from the start. This pretty much makes it dubious a a plate amp for a sub.
- I would want to study the SOA a bit more; with a 4 ohm speaker or a nominal 8 ohm that has big dips you may have less power than available than first appears. The 30A current figure doesn't mean much when you match it against the voltages you are more likely to require.
-- There is no info on clipping characteristics: clean, soft, ugly. . .?
I'm not nocking it. It would be fun to mess with if they were giving them away for free. It has the both the principal pluses and minuses of any IC amp: it lets you build an amp with few parts but you are limited to what it is. In passing, I wonder if it can be bridged.
Remember Crown?
Crown started out building power amps used for servo motor and shake table control application in the seventies. Thier products where "discovered" for audio applications. Apex may be another case.
It doesnt look like the economics make much sense, since you could use multiple LM 3886s (etc) to achieve the same power levels.
We need to find someone who has heard them in action.
Crown started out building power amps used for servo motor and shake table control application in the seventies. Thier products where "discovered" for audio applications. Apex may be another case.
It doesnt look like the economics make much sense, since you could use multiple LM 3886s (etc) to achieve the same power levels.
We need to find someone who has heard them in action.
Bridging the PA05
The PA05 can be bridged in a parallel, series or series - parallel configuration:
The have stated in the application notes that the amplifiers will operate well under these configurations and offer sample designs.
http://eportal.apexmicrotech.com/mainsite/support/pages/app_notes.asp?guid=
Could you imagine getting 6 KiloWatts from a dozen of these amps in series / parallel configuration?
The PA05 can be bridged in a parallel, series or series - parallel configuration:
An externally hosted image should be here but it was not working when we last tested it.
The have stated in the application notes that the amplifiers will operate well under these configurations and offer sample designs.
http://eportal.apexmicrotech.com/mainsite/support/pages/app_notes.asp?guid=
Could you imagine getting 6 KiloWatts from a dozen of these amps in series / parallel configuration?
PA05 Price (US Dollars)
Apex products may have multiple grades available
Price:
PA05 Op-Amp, 100V, 30A EA $279.08
PA05A Op-Amp, 100V, 30A EA $345.53
This seems a little pricey, but I think it is worth it, if you read up on this product they offer excellent protection from current and thermal overload. I read that the military uses Apex products, and I can see why.
1.) They are hermetically sealed.
2.) They have high G-Force ratings.
3.) They are high performance and very compact.
Perfect for sonar and weapons of mass destruction.
Apex products may have multiple grades available
Price:
PA05 Op-Amp, 100V, 30A EA $279.08
PA05A Op-Amp, 100V, 30A EA $345.53
This seems a little pricey, but I think it is worth it, if you read up on this product they offer excellent protection from current and thermal overload. I read that the military uses Apex products, and I can see why.
1.) They are hermetically sealed.
2.) They have high G-Force ratings.
3.) They are high performance and very compact.
Perfect for sonar and weapons of mass destruction.
Hermetic
Hermetic Means Sealed, airtight or enclosed.
Typically an amplifier of the equal in performace to the PA05 is made of discrete components that use huge amounts of PCB real estate.
Discrete amplifiers have many delicate components that can be damaged easier by High G-Forces and contamination.
Hermetic Means Sealed, airtight or enclosed.
Typically an amplifier of the equal in performace to the PA05 is made of discrete components that use huge amounts of PCB real estate.
Discrete amplifiers have many delicate components that can be damaged easier by High G-Forces and contamination.
I will be first.
Speaker, I am not you typical audio enthusiast. I am not a vaccum tube hugging hippy. Down the road, amplifiers will simply be a slab of silicon with 3 pins going to the power supply the 4 pins to the PCI Express bus and two more pins out to the load (filterless).
For all you non believers, deal with it.
Speaker, I am not you typical audio enthusiast. I am not a vaccum tube hugging hippy. Down the road, amplifiers will simply be a slab of silicon with 3 pins going to the power supply the 4 pins to the PCI Express bus and two more pins out to the load (filterless).
For all you non believers, deal with it.
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