| Wynand |
Hi I've been building the Mauro Rev A amp and is nearly ready to start her up. I've got a trafo for 24VDC and would like to use this just to check that it works.
Is this voltage too low? I know 32 volts is what is recommended.
PS I have read the mauro thread upto page 50 something and haven't seen something to help me, maybe I missed it. |
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| Russ White |
| quote: | Originally posted by Wynand
Hi I've been building the Mauro Rev A amp and is nearly ready to start her up. I've got a trafo for 24VDC and would like to use this just to check that it works.
Is this voltage too low? I know 32 volts is what is recommended.
PS I have read the mauro thread upto page 50 something and haven't seen something to help me, maybe I missed it. |
It will work, but not very well. You could make it work better by reducing the shunt reg resistors to something like 800R instead of 1K.
The problem will be that the LM318 will be slightly starved for current, and the shunt reg will be operating outside its ideal range.
But for testing it should be fine.
Cheers!
Russ |
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| Wynand |
Thanks for the reply Russ, while you're here there's another Q
I read that you didn't like the initial sound of the REV C.
Was that because you soldered the components onto Mauro's pcb layout? (The one I'm using)
I want to try the REV C but don't want to stuff everything up.
PS are there Gerbers availably for mauro's layout.
The reason I ask is that I may be able to get PCBs made professionally as a favour (just for me and my boss) |
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| Russ White |
Yes I think my initial impression of Rev C was more about my shortcomings soldering the thing up then anything else. :) Rev A is awefuly good, and some will like it better than Rev C. Rev C to me seems to have better sound stage and imaging. Rev A may have a bit more air, but that is highly subjective. My opinion is I like them both. :D
Cheers!
Russ |
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| Russ White |
| Contact me privately about the gerbers, I may be able to get you something. |
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| Wynand |
Great.
Now I don't know which way to fall!!!:clown: |
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| Wynand |
I'll probably start with REV A but those graphs of the phases looked way better on the Rev C.
What about listener fatigue(I heard you guys talk about that). I'd like to be able to listen to the amp alot. Won't this count against the Rev A?
Sorry for all the Q's but I don't know about listening fatigue and stuff. |
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| Russ White |
| Ok, since you prodded me... If I was only given to choice to build one. I would build Rev C. :) I just really love the precise soundstage. Fatigue has never been an issue for me with either design. |
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| Wynand |
Thanks, Rev C it is!!!:D
I've sent you a mail.:) |
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| Panelhead |
I built several versions of the A and the C. In my very low output application the C version is more linear and extended at the frequency extremes. This is sub 1 watt levels at all times.
If your power needs are higher, the lower distortion of the A version may be better. The two do sound very different, at least when pumping out a 100 mW at peaks.
Both are very good. I am waiting to build the SuSy amp next.
George |
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| derekyu |
Can someone share with me?
I use the 1uf Auricap for Rev A(as the input cap) and try to parellel with a 10uf or 20 or some value BP cap.
Is it good for sound? |
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| Russ White |
| quote: | Originally posted by derekyu
Can someone share with me?
I use the 1uf Auricap for Rev A(as the input cap) and try to parellel with a 10uf or 20 or some value BP cap.
Is it good for sound? |
The 1uf cap alone should be sufficient. You could increase the input impedance a bit you if like by replacing the 100K resistor on input. This would give you a bit lower corner frequency at the possible cost of slightly more line noise.
I prefer to use a single cap and not parallel caps, but that might just be personal taste.
:EDIT: If you know your amp will always be following a source with no DC offset on output omit the input cap alltogether, this will improve the sound significantly.
Cheers!
Russ |
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| derekyu |
Russ Thanks for sharing.
I try to parellel a 100k with the input 100k and feel that much more lower frequency was obtained. Am I right?
Or the higher the K in value, more low frequency will be get? |
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| Russ White |
| The higher the input impedance the lower the corner frequency of the high pass filter. |
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