first part - of course, suitable series resistor then cap to GND
though, simple cascode is solution where you're keeping everything under control
second part (increasing bias) , I'm not following you there - gimme more details
Check out this vid about peltier devices - the important bit is the demo on just how effective a fan is at removing heat - you can do a huge amount with baffles to stop fan noise escaping whilst still having airflow. BUILD YOUR OWN REFRIGERATOR! - SOLID STATE TEC - YouTube
Thanks for the responses. 24V should be enough, unless some have found that higher supply voltages result in better sound.
I was thinking of LPS because SMPS can be noisy unless well built. If the quality is good, then SMPS will work. As far as unregulated goes, I am not afraid of big caps.
I was thinking of LPS because SMPS can be noisy unless well built. If the quality is good, then SMPS will work. As far as unregulated goes, I am not afraid of big caps.
This has very likely been covered before but I could not find it by searching this forum. On his YouTube channel Steve Guttenberg gave a glowing review of the ACA both as a stereo amp and as monoblocks. He mentioned that using them as monoblocks via XLR cancelled out the second harmonic distortion and dramatically changed the sound characteristic (for the better in his opinion).
Would this same change occur from running the amps as monoblocks via RCA instead of XLR?
Would this same change occur from running the amps as monoblocks via RCA instead of XLR?
You get the benefits of the increased power but if running from RCA the second harmonic isn’t being “cancelled” or whatever they described it as. (I.E., that’s not actually what’s happening...)
Does it sound different SE bridged vs XLR, yes. A little. Both sound great and the benefits of running them mono bridged is wildly better than stereo. You’ll love it.
Does it sound different SE bridged vs XLR, yes. A little. Both sound great and the benefits of running them mono bridged is wildly better than stereo. You’ll love it.
Here's a newbie question: Can anyone tell me relative output impedance for the four possible configurations, stereo, monoblock balanced, monoblock bridged and monoblock parallel?
Don't need actual figures just ranking, thanks.
Mario
PS: will be making stereo version this weekend and have two mono's on order (already received the monos' chassis...love the backplate!)
Don't need actual figures just ranking, thanks.
Mario
PS: will be making stereo version this weekend and have two mono's on order (already received the monos' chassis...love the backplate!)
Possibly there has been a second revue, but my recollection of his rave review was that he constantly mentioned “stereo” or “balanced” as the 2 options. There are actually 4 options, and the cool thing is that they are actually different sounding, depending on the other components, esp. Speakers.
1. the “2ch/stereo mode” as in the past.
2. the “balanced monoblock” mode which has the switch in the middle position, accepts input from the XLR connection, and only works with a balanced preamp.
3. the “bridged monoblock” mode which accepts a standard unbalanced input into an RCA connector. This should have more “good” distortion but it would be less than you think because it’s “kinda balanced internally” and some distortion is balanced out. It should work well with speakers that need a bit more power.
4. the “parallel monoblock” mode which also uses one RCA connector, and should work well with 4 ohm speakers, but also with “nominal 6 or 8 ohm speakers with big impedance dips in frequency response.
So there are lots of choices as per the chart above and really you can’t predict it. Just try ‘em all and see which you like! It’s fun!
But the confusing thing is it appears that Steve only tried “stereo” and “balanced monoblock” as I’ve mentioned above, “balanced” would only be the correct term if he’s using a balanced preamp. I kind of suspect he meant “bridged” but maybe he was using a balanced preamp. I’d love to know.
We are of course thrilled with his review. However I was very interested in how he liked all 4 options with his 2 choices of loudspeaker. Seems like it would be another great episode.....
Oh, and we upgraded the old 19v SMPS power brick a lot with a MeanWell 24v brick (at 5 times the cost) starting at the V1.6 version. Measures much quieter and more powerful. I recommend the upgrade for all older ACAs.
1. the “2ch/stereo mode” as in the past.
2. the “balanced monoblock” mode which has the switch in the middle position, accepts input from the XLR connection, and only works with a balanced preamp.
3. the “bridged monoblock” mode which accepts a standard unbalanced input into an RCA connector. This should have more “good” distortion but it would be less than you think because it’s “kinda balanced internally” and some distortion is balanced out. It should work well with speakers that need a bit more power.
4. the “parallel monoblock” mode which also uses one RCA connector, and should work well with 4 ohm speakers, but also with “nominal 6 or 8 ohm speakers with big impedance dips in frequency response.
So there are lots of choices as per the chart above and really you can’t predict it. Just try ‘em all and see which you like! It’s fun!
But the confusing thing is it appears that Steve only tried “stereo” and “balanced monoblock” as I’ve mentioned above, “balanced” would only be the correct term if he’s using a balanced preamp. I kind of suspect he meant “bridged” but maybe he was using a balanced preamp. I’d love to know.
We are of course thrilled with his review. However I was very interested in how he liked all 4 options with his 2 choices of loudspeaker. Seems like it would be another great episode.....
Oh, and we upgraded the old 19v SMPS power brick a lot with a MeanWell 24v brick (at 5 times the cost) starting at the V1.6 version. Measures much quieter and more powerful. I recommend the upgrade for all older ACAs.
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The table you posted (8801 and 9070) contains errors, where did you get it ? In particular I question the numbers for 16 Ohm load. They should be about 55% the 8 Ohm numbers.
Nelson posted graphs for v1.6 in post 8788. After I said I disagreed with his numbers, he said he liked my numbers better in post 8810. It has not been determined why the numbers were so different.
I think I can make a pretty legit case that the spellcheck would see what I wrote, cascoding, and change it to cascading. In fact it just did it in this message too!
You should call it the Hotrod Kampala ACA!
It is straight from the V1.6 build guide step 54 (Amp Camp Amp V1.6 Build Guide - diyAudio Guides) highlight ACA Operation Modes. I do not know who created it.
I see no reference to 16 ohm loads in the posts you numbered, #6200, #8788, #8810. And which parameter does 55% refer to? Can you please clarify?
Alan