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Cheap Balanced Power Amplifier - Chip or Class D

glenn jarrett said:
HI Julf

the B4 has single ended output what i want to do is find the best way of driving the amps
from what i have read you need a balanced input or a phase splitter for the amp input
or have i got it wrong ?
whats the best way to go from single ended to balanced
or can i drive it from a single ended input

http://www.icepower.dk/files/solutions/icepower50asx2_designersmanual_1-1b_03072012.pdf

http://www.icepower.bang-olufsen.com/files/solutions/icepower50asx2.pdf
Click to expand...

Yes, you can drive a differential/balanced input from a single-ended source without problems, but... Both of those show the modules a) being single-ended, and b) being driven by single-ended sources but... The BTL diagrams show a separate phase inverter that doesn't seem to be included in the icepower modules. Is that why you need a balanced output - to get the inverted output to drive one half of a (single-ended) bridge?
 
Hi Julf
yes thats what i assume from what i have read about it
its all working and sounds good just wondering if i can remove the drv134 or if it is needed is there a better way to do this ?
 
glenn jarrett said:
Hi Julf
yes thats what i assume from what i have read about it
its all working and sounds good just wondering if i can remove the drv134 or if it is needed is there a better way to do this ?
Click to expand...

You need something to generate the inverted signal. It would be easier if the icepower amps had differential/balanced inputs. As they are single-ended, something is needed - a transformer, op-amp or a inverting/non-inverting buffer like the drv134.
 
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My second ICE board and differential/balance board have arrived so I just now need the time to make a psu board and connect it all up.

Pete
 
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just tried the OPA1632 boards but they have not got enough gain so i have gone back to the DVR134
over the next few weeks i will build this amp into a nice case with remote control vol, input ,on / off
36350028742_25a6421501_k.jpg
[/url]20170812_112334 by glenn jarrett, on Flickr[/IMG]
 
works fine with the DVR134 but when replaced with the OPA1632 you only get very low volume level
( with vol pot on full )
the dvr is 2x gain
looks like the opa gain is very low ( tiny pcb size of a stamp so wont be trying to unsolder resistors and replacing them )
will stick with the dvr
 
Update on Ice Power Modules:
I now have my original ice power module re-fused, and working, and have now built the other two, so I have three tiny power amps, measuring 6" x 4" x 1" though the speaker binding posts add another inch to the thickness! Very minimalist with no indicator lights, etc. They are now in use in my kitchen speaker system, and they sound at least as good as my gaincone and chip amp setup. I think I may try comparing them to my gainclones driving my Quad ESL57s in the TV system, as they would look quite good sat on the Quad's OTA stands, as they look a bit like miniature valve amps. Total cost was £25 each, for a (sort of) 50W power amp is really pretty good. Now need to find a use for a couple of perfectly decent Muse class D amps.
 
I have mine up and running into my Arcs, it doesn't sound half bad, I need to pop the Hackernaps back and mod it into a bridged one with the extra board I have had for some weeks now.

Pete
 
glenn jarrett said:
works fine with the DVR134 but when replaced with the OPA1632 you only get very low volume level
( with vol pot on full )
the dvr is 2x gain
looks like the opa gain is very low ( tiny pcb size of a stamp so wont be trying to unsolder resistors and replacing them )
will stick with the dvr
Click to expand...

Maybe that because OPA's was fake? I never seen OP amps from china that were genuine. Especially burr-browns and TI's amps. There are very many fakes on ebay.
 
glenn jarrett said:
just tried the OPA1632 boards but they have not got enough gain so i have gone back to the DVR134
over the next few weeks i will build this amp into a nice case with remote control vol, input ,on / off
20170812_112334 by glenn jarrett, on Flickr
Click to expand...


I can't help thinking your earth lead on the transformer bolt and earthed input socket are creating a shorted turn, I might be wrong but its something you need to look at.

I can also download your images from flickr, you need to check your settings in Account settings/privacy & permissions.

Pete
 
Hi Glenn,
do you have any links for the ASX50 cable looms ?

I've found the JST PH ones,
http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=172777176446 - 7 Pin 1.25mm pitch - Signal
http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=172777176446 - 3 Pin 1.25mm pitch - Aux

Not sure about the JST VH variant though.

Are these the 3.96mm pitch ones?

No female cable sets as per PH ones, apart from the expensive ones sold by Ghent Audio.

Looking at the photo of the one you assembled, you're using little green screw down connectors, what are they called ?

I've seen PH,XH,micro, mini designations.

Are they known under a more generic name ?
 
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Pete MB&D said:
I bought my connectors and pins from Rapid, and made my own cables.

Pete
Click to expand...

thanks Pete, I'll look on Rapid.

Would prefer the ready made leads, as the JST looks a little fiddly.

I'm in 2 minds whether to solder directly on to the pins and use a bit of heatshrink, since they're a decent size, but it would be neater and safer potentially to use the connectors.
 
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