Will RevA run with 24volt rails?

Wynand · 6th July 2006, 12:12 PM

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.

Russ White · 6th July 2006, 12:24 PM

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

Wynand · 6th July 2006, 12:35 PM

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)

Russ White · 6th July 2006, 12:38 PM

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.

Cheers!
Russ

Russ White · 6th July 2006, 12:40 PM

Contact me privately about the gerbers, I may be able to get you something.

Wynand · 6th July 2006, 12:40 PM

Great.

Now I don't know which way to fall!!!

Wynand · 6th July 2006, 12:43 PM

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.

Russ White · 6th July 2006, 12:45 PM

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.

Wynand · 6th July 2006, 12:52 PM

Thanks, Rev C it is!!!

I've sent you a mail.

Panelhead · 6th July 2006, 04:58 PM

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

6th July 2006, 12:12 PM	#1
Wynand diyAudio Member Join Date: Mar 2005 Location: Cape Town	Will RevA run with 24volt rails? 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.

6th July 2006, 12:38 PM	#4
Russ White diyAudio Member Join Date: Jan 2005 Location: Nashville, TN, USA	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. Cheers! Russ __________________ Less pulp more juice Twisted Pear Audio.

6th July 2006, 12:40 PM	#5
Russ White diyAudio Member Join Date: Jan 2005 Location: Nashville, TN, USA	Contact me privately about the gerbers, I may be able to get you something. __________________ Less pulp more juice Twisted Pear Audio.

6th July 2006, 12:45 PM	#8
Russ White diyAudio Member Join Date: Jan 2005 Location: Nashville, TN, USA	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. __________________ Less pulp more juice Twisted Pear Audio.

6th July 2006, 04:58 PM	#10
Panelhead diyAudio Member Join Date: Dec 2002 Location: Houston	My 2 cents 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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6th July 2006, 12:35 PM	#3
Wynand diyAudio Member Join Date: Mar 2005 Location: Cape Town	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)

6th July 2006, 12:43 PM	#7
Wynand diyAudio Member Join Date: Mar 2005 Location: Cape Town	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.

6th July 2006, 12:52 PM	#9
Wynand diyAudio Member Join Date: Mar 2005 Location: Cape Town	Thanks, Rev C it is!!! I've sent you a mail.

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