These are makerbeam extrusion aluminium profiles - https://www.amazon.com/MakerBeam-30...rial&sprefix=makerbeam+,industrial,288&sr=1-6
Sweet! I have used Makerbeam XL for a handful of projects. Love the stuff. The right angle brackets in your pictures made me think it was another brand.
I am now listening with 0.22R power resistors and the bias being 0.710v with the heat manageable over my heat sinks. The gain and power is very good with my 4 ohm load PAP speakers and for the first time I can actually listen in low volume without loosing any of the details paired with the HPA clone preamp and Aya 5 being the source.
Will it give me any benefit in changing the resistors to 0.15R to increase the bias apart from more heat?
Will it give me any benefit in changing the resistors to 0.15R to increase the bias apart from more heat?
I do not believe in increasing quiescent if your amp is NOT clipping.
There is no benefit if your amp is free of clipping during the listening sessions.
HD
There is no benefit if your amp is free of clipping during the listening sessions.
HD
Ηi Mr Hugh .
Listening to music at high volume, one would not be able to distinguish the weakness of the amplifier due to low quiescent current, harsh music tone.....?
This (bias current) is a very interesting Qu! 👍
I assume - having 4 ohm spkrs - you built the AN4R?
If so - surely 0.12R is the recommended Source resistor value???
Now, Hugh said this:
This makes a lot of sense; I recently increased the Source resistors in my AN4R from 0.12R to 0.15R - ie. reduced the bias current ... in order to reduce heat output (so I could use the amp for more months of the year).
There does not appear to be any resulting decrease in SQ - and I am still not clipping with my spkrs.
I guess it depends on:
* how loud is 'high volume', and
* do your spkrs drop below 4 ohms?
Certainly, at my listening levels and with my spkrs (active - so, having no passive XO ... a fairly constant 4R) ... there is no harshness.
I assume - having 4 ohm spkrs - you built the AN4R?
If so - surely 0.12R is the recommended Source resistor value???
Now, Hugh said this:
This makes a lot of sense; I recently increased the Source resistors in my AN4R from 0.12R to 0.15R - ie. reduced the bias current ... in order to reduce heat output (so I could use the amp for more months of the year).
There does not appear to be any resulting decrease in SQ - and I am still not clipping with my spkrs.
I guess it depends on:
* how loud is 'high volume', and
* do your spkrs drop below 4 ohms?
Certainly, at my listening levels and with my spkrs (active - so, having no passive XO ... a fairly constant 4R) ... there is no harshness.
What do you mean with "weakness of the amplifier due to low quiescent current"...??
Either the amp runs out of steam (clipping), or it bursts into distortion because of some design error, which is not the case.
Either the amp runs out of steam (clipping), or it bursts into distortion because of some design error, which is not the case.
Hi my friend Andy .
how do see this? from clip led? or from test gen and scope with load 4Ω?
I don't have any diagram response chart of these speakers, for this and I went to 2.6A to be sure ....but my ears also heard this at high volumes like listening to mp3 vs flac ....hahaha
First, I measured the clipping level with a resistive load from 6 ohms down to 2 ohms (and posted my results). From memory, the red clip LEDs came on before the scope showed a clipped sine wave for 6R, 4R and 3R loads - but at 2R load, the sine wave clipped before the red LED lit up.
Listening with my spkrs, I did see the red LEDs light up briefly, with some tracks.
Then, on Hugh's suggestion, I changed the +ve rail mosfet for a BJT - and, unfortunately, this stopped the clip LEDs from working! 🙁
Mmmm ... you would seem to listen much louder than I do! 😀 Or your spkrs are less efficient than mine. 😵
Hahahaha yes....Proson or JWS Speakers inside i think....
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How can you test actual clipping, without a load?
To me, the results you get (using a scope to look at the clipped sine wave) only make sense when there's a load resistor attached? Then you can work out what power output it's clipping at.
Yes Andy it clips and the led goes on .
i will post with load later..
do you have any images square with load?