Recommend an Amplifier for twin woofers

[ttan98]

Christi

I like to build an amplifier which must be able drive my twin woofers connected in parallel to give between 3-4ohms.

I have a power supply which will give me about +/-70Vdc and I need at least 125W into 8 ohms and 250W into 4 ohms. More power output from the amplifier is a bonus.

You have many modules which will fit this criteria, I need the power output to be clean and ability to drive these loads. Please recommend me a few models which I can look at your website and I will decide from there.

Thanks.

 

[Cristi]

Starting from the voltage value of the available power power supply, i can only recommend this boards: Connexelectronic
at +-70V the amplifier can deliver about 400-500W on a 4R impedance or at least 200W on 8R. having higher supply voltage will give you a reserve and better dynamic, the amp will be far from clipping at any time if you only need 250W. make sure that you have enough capacitance for the caps from the power supply, using the amplifier for low-frequencies, otherwise the supply voltages will boost beyond the overvoltage threshold and the amp will mute every time when play loud low frequencies. i recommend at least 4700uF per rail for each module when supply them at +-70V.

 

[ttan98]

Hi,

Do you have them in stock now incl. instruction sheets or do I have to wait for its availability?

 

[glt]

Hi Cristi,

Your new amp coupled with the resonant supplies are perfect for subs application. But there is a need of a simple module with summing R+L input, configurable low pass filter and some amount of level control. Any plans for such a module?

 

[ttan98]

Hi,

Does this module, IRS2092 needs a speaker protector outboard? or Does it has a built-in speaker relay?

 

[col]

also, the thing I ALWAYS need but no DIY designer bothers with is a clipping light.

 

[Cristi]

Glt, thank you for the suggestion, as i mentioned some months ago, there are so many things that can be done, unfortunately there is no time for everything, and i must filter the ones which are required the most, if there are other requests too, i consider to design it.

The IRS2092 Modular Amplifier has speaker protection relay on board. i know, some of you guys will say that is useless, the ic has silent start, short-circuit protection, etc. but for an amplifier module, not a complete product, there is always good to have one more level of protection, especially when there are modules with different supply voltage requirements, the lowest power one has 100V Vds transistors, and this can be definitely killed if is supplied with +-80V as is required for the 600W one. I already have a customer which bought 6 of these modules, 2 are 150W, 2 are 250W and 2 are 600W for an active filter amplifier. by mistake, it can be easy to connect the 150W module instead of 600W one since they share the same housing. the relay will not connect the speakers in this case.

Col, some of the amplifiers ic's have built-in clipping, such as LME49810 others require an external circuit. i will consider this suggestion as well.

 

[ttan98]

Cristi,

You haven't answer my question, is the +/- 70Vdc IRS2092 module in stock and the instruction sheets that go with them?

 

[Cristi]

I have the amplifier modules on stock. i can ship them just next week, the shipping company hasn't started work yet, due to Chinese New Year holiday. I will write the manual in the following weeks, as soon as i have some free time for this. till then, i just ask me what is unclear and i will answer.

 

[ttan98]

Advise me when the post office reopens after holidays, I will place order then.

 

[Cristi]

The shipping company opened today, i just came from there. they start collecting packages and hopefully send till end of this week. it was closed for more than 2 weeks, and now was totally craziness over there... they should have made a population census there, for sure would exceed the known numbers )

 

[androuski]

Hi Cristi,
I wonder about IRaudamp7's distortion beyond 1khz, especially while driving low load, between 2,5 and 4ohms. What do we know about this ?
Regards

 

[androuski]

Another q° : actually this amp would drive a 90db fullrange speaker, with a 2,8ohms load between 80 and 160hz. What is the right IRS2092 Modular Amplifier version to choose (high or mid voltage ?) to cope with such a load ? Will this IRS amp designed to drive such rogue-Z speaker ?
Regards,
Androuski

 

[Cristi]

For 4R impedance and below i recommend the IRS2092 amplifier modules, Connexelectronic the 400W and 600W versions are able to deliver up to 500W and 900W into 2R with forced air cooling and THD below 0.5%. for the 600W module, the maximum power which i could squeeze while the THD was below 1% at 4R was 740W and at 2R was 1030W then the module enters in over-current protection. these tests were done while the module was supplied at +-91V and cooled with a fan blowing through the heatsink and board. I use for measurements the VA2230 audio analyzer. unfortunately i have no pc interface to be able to save the plots in a grafic format as the audio precision analyzers can, but i make the measurements at few key frequencies and read the results.

 

[cOz]

What is the input impedance of this module?

 

[androuski]

For 4R impedance and below i recommend the IRS2092 amplifier modules, Connexelectronic the 400W and 600W versions are able to deliver up to 500W and 900W into 2R with forced air cooling and THD below 0.5%. for the 600W module, the maximum power which i could squeeze while the THD was below 1% at 4R was 740W and at 2R was 1030W then the module enters in over-current protection. these tests were done while the module was supplied at +-91V and cooled with a fan blowing through the heatsink and board. I use for measurements the VA2230 audio analyzer. unfortunately i have no pc interface to be able to save the plots in a grafic format as the audio precision analyzers can, but i make the measurements at few key h=frequencies and read the results.

Thanks for your reply Cristi
I've got 2 500VA 2x35v transfomer, which gives 49v after rectifiers : is this ok for a 150w version ?

I don't need 500w, and 0,5% is pretty high ; do you know until which limit the distorsion remains below 0,05%, for instance on the 150 or 250w IRS2092 version ?