orson whitfield
Well-known member
I wonder if Jeff Rowland gear comes with schematics? Because if so my friend owns a very expensive pair of mono blocks. Let me know.
Anyone want to build me another one of these?
- Thread starter bblackwood
- Start date
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bblackwood
Active member
- Joined
- Jun 3, 2004
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- 33
[quote author="Kev"][quote author="Bear"]And Kev, when you're talking about powering the mains, you're talking about soffit mounted big boys, not NS-10's, right?
[/quote]
yeah but even with NS10's I think you can afford to have a little more ... not so much about the shear wattage but the volts ... all about the volts.
[/quote]
I dunno, without hearing it, that statement sounds like you're assuming a lot based on numbers alone...
This thing is brutally powerful.
[/quote]
yeah but even with NS10's I think you can afford to have a little more ... not so much about the shear wattage but the volts ... all about the volts.
[/quote]
I dunno, without hearing it, that statement sounds like you're assuming a lot based on numbers alone...
This thing is brutally powerful.
Kev
Well-known member
When you run out of volts ... the amp will clip ...
Brad, I trust your ears. When you amp clips I'm sure you turn down the gain.
So far there has not be a single person that I have installed a clip indicator into their power amp that latter didn't up grade to an amp with more rail voltage and move their old amp to secondary monitoring or headphones.
Don't assume that everyone has your knowledge or experience. People often need to be shown stuff before they truly understand.
The number of times I've had to explain out of phase / reverse polarity speakers ... and then demonstrate ... it's depressing.
especially with vidoe editors ... the look of horror when you show them the problem of a stereo news report that is in silence on a mono TV ...
I walked into a very High class Hi Fi shop and past a pair of tower speakers ..
I winced ...
" Your mid or tweet is out of phase "
" How do you know ? "
" My eyes are watering and it almost hurts"
A few exchanged words and then the manager walked in ... he is a friend.
Give Kev a screw driver.
Minutes later I have both mids out on the floor ... a 1.5 volt battery told us that one mid was incorrectly marked for positive as the two cones moved in different directions .... :shock:
I told the guys to get their techs to double check my work as I was assuming a 12dB filter and looked at the woofer to try to make an intelligent guess at what the polarity of the mid was supposed to be.
I didn't bother to have a good listen as I was hungy and the manager and I left to go have some lunch. As we left I heard them say ...
" Wow the vocals are so much more centred and defined. "
No I'm not a ledgend or hero but I'm glad they were happy. This really is simple stuff that more people should be able to understand and recognise.
Sure, that was all a bit OT ... but ... the simple things. Likewise, if you run out of volts it must clip. Too many people try to run un-compressed music with out headroom. Drums , banjos, even shakers ... perhaps especially these small percussion instruments can send the little 50 watt and 88dB 1w/1m speaker combinations into clipping.
I can give you a servo amp that might be 25w into 8 ohms and might be capable of massive amounts of current that on paper would be thousands of watts into near short circuits. Great for servo motors on control surfaces of aircraft etc. Might even make for a good sounding audio amp BUT it is likely to be a strange balance of current verses volts for a 25 watt audio amp.
It is all about application and requirements.
There was a time when speakers were rated for volts and I guess I still think that way. 25 watt speaker doesn't mean 25 watt amp ... yes I know no-one hear would think that way.
I'll shut up now ... we have done this merry go round many time before.
sorry
almost finished !!
Brad,
this amp could be DIY'ed but is it worth it ?
How much is the original ?
Add up the cost of a 1.2 kVA power trafo and 20 x 10000uf quality caps and then add in the 32 (??) output devices ... ( what is this device ? )
and you will have a starting price ..
and the heatsinks and the rack box.
I think that will be the bulk of the cost of the unit.
Perhaps one of these will turn up second hand. Get some spare output devices for the future and make sure you can keep this beast running for many years to come.
I really can see what is inside this beast and can see why you like it. :thumb:
Brad, I trust your ears. When you amp clips I'm sure you turn down the gain.
So far there has not be a single person that I have installed a clip indicator into their power amp that latter didn't up grade to an amp with more rail voltage and move their old amp to secondary monitoring or headphones.
Don't assume that everyone has your knowledge or experience. People often need to be shown stuff before they truly understand.
The number of times I've had to explain out of phase / reverse polarity speakers ... and then demonstrate ... it's depressing.
especially with vidoe editors ... the look of horror when you show them the problem of a stereo news report that is in silence on a mono TV ... I walked into a very High class Hi Fi shop and past a pair of tower speakers ..
I winced ...
" Your mid or tweet is out of phase "
" How do you know ? "
" My eyes are watering and it almost hurts"
A few exchanged words and then the manager walked in ... he is a friend.
Give Kev a screw driver.
Minutes later I have both mids out on the floor ... a 1.5 volt battery told us that one mid was incorrectly marked for positive as the two cones moved in different directions .... :shock:
I told the guys to get their techs to double check my work as I was assuming a 12dB filter and looked at the woofer to try to make an intelligent guess at what the polarity of the mid was supposed to be.
I didn't bother to have a good listen as I was hungy and the manager and I left to go have some lunch. As we left I heard them say ...
" Wow the vocals are so much more centred and defined. "
No I'm not a ledgend or hero but I'm glad they were happy. This really is simple stuff that more people should be able to understand and recognise.
Sure, that was all a bit OT ... but ... the simple things. Likewise, if you run out of volts it must clip. Too many people try to run un-compressed music with out headroom. Drums , banjos, even shakers ... perhaps especially these small percussion instruments can send the little 50 watt and 88dB 1w/1m speaker combinations into clipping.
I can give you a servo amp that might be 25w into 8 ohms and might be capable of massive amounts of current that on paper would be thousands of watts into near short circuits. Great for servo motors on control surfaces of aircraft etc. Might even make for a good sounding audio amp BUT it is likely to be a strange balance of current verses volts for a 25 watt audio amp.
It is all about application and requirements.
There was a time when speakers were rated for volts and I guess I still think that way. 25 watt speaker doesn't mean 25 watt amp ... yes I know no-one hear would think that way.
I'll shut up now ... we have done this merry go round many time before.
sorry
almost finished !!
Brad,
this amp could be DIY'ed but is it worth it ?
How much is the original ?
Add up the cost of a 1.2 kVA power trafo and 20 x 10000uf quality caps and then add in the 32 (??) output devices ... ( what is this device ? )
and you will have a starting price ..
and the heatsinks and the rack box.
I think that will be the bulk of the cost of the unit.
Perhaps one of these will turn up second hand. Get some spare output devices for the future and make sure you can keep this beast running for many years to come.
I really can see what is inside this beast and can see why you like it. :thumb:
SonsOfThunder
Well-known member
Just for grins, Brad, email Nelson and ask him how long it takes to set this amp up in final adjustment... If my suspicions are correct, we'll all be very surprised by the answer.
btw, anyone ever look at the Bryston schematics at their site? Notice that the main part numbers resemble common parts but have funny alpha prefixes? Someone should email them and ask why... If anyone posts these answers, I'll tell what I have heard from someone who knows...
Peace!
Charlie
btw, anyone ever look at the Bryston schematics at their site? Notice that the main part numbers resemble common parts but have funny alpha prefixes? Someone should email them and ask why... If anyone posts these answers, I'll tell what I have heard from someone who knows...
Peace!
Charlie
SonsOfThunder
Well-known member
Kev,
I'm totally with you on this...Lots of people in the world can't listen. A large part of listening is interpreting what we all hear. That additional processing is what separates the really talented people, IMO.
[quote author="Kev"]Brad, I trust your ears. When you amp clips I'm sure you turn down the gain.[/quote]I'd be really surprised if he EVER gets this amp near clipping unless his monitors are VERY power hungry.
Charlie
I'm totally with you on this...Lots of people in the world can't listen. A large part of listening is interpreting what we all hear. That additional processing is what separates the really talented people, IMO.
[quote author="Kev"]Brad, I trust your ears. When you amp clips I'm sure you turn down the gain.[/quote]I'd be really surprised if he EVER gets this amp near clipping unless his monitors are VERY power hungry.
In the industry that I work in for my day job, more clipping=louder amp="gooder"/better/more. Whatever... it pays my mortgage.:green:
No doubt about this at ALL, dude! Much of the time people still don't understand the explanation/demonstration...sometimes they just don't care!
I know this sounds really arrogant, but I have had to learn to just keep my mouth shut when I go into any electronics shop, period.
It happens, but should never have left the factory. This is inexcusably poor QC, except for maybe $100/pair speakers.
No, Kev, you have the ability to listen (hear AND process)...sorry to tell you but most people just don't know and probably never will, I'm afraid. I've worked in audio since 1986...retail, wholesale, etc. Some people will learn, some people won't learn and some just don't have the inborn ability to learn it, some don't care. This is okay with me, disappointing sometimes, frustrating sometimes, but okay nonetheless.
In 'real deal' PA, the rule of thumb :thumb: is RMS AMP POWER = 4x to 10x peak rating of speaker. I like it!
My turn to shut up now! Wheee! This is a fun ride!
Perhaps yellow marshmellow llamas will fly out of my rear end!! :green:
Charlie
Kev
Well-known member
thanks guys
yeah ... I just have to learn to keep my mouth shut
I just get so frustrated
the simple thing can often be where audiophoolery starts
Hey Dave,
the Pass DIY site was a like of the week at the old place.
I recall him talking about that ...
I think it is about time I downloaded a new version 7 of his ZEN stuff.
http://www.passdiy.com/pdf/zen-v7.pdf
:thumb:
I'll grind away just one more time :
In the PA world in the early eighties we all had just a couple of designs of amps and one paper they where all very similar and close to there original application notes for the output devices.
All had brochures quoting the same stuff +/- a little.
We all ended up choosing the ones with the higher rail voltage and most important was that we ended up putting on the top end. It was the gutless amp. Had the voltage but not enough power supply or enough output devices in parallel. It was smaller and lighter. A good balance of cost and performance.
There was a lower wattage version of the gutsy amp but this wasn't used as it didn't have the volts BUT did return the same power figures into 2 ohms as the above amp.
Given you have the current for the application it seems that the volts directly relates to headroom/ level.
During recording a mic-pre amp has headroom. How much headroom is required ?
Should the following line stages have the same headroom ?
Should the amp/speaker system have the same headroom ?
yeah ... I just have to learn to keep my mouth shut
I just get so frustrated
the simple thing can often be where audiophoolery starts
Hey Dave,
the Pass DIY site was a like of the week at the old place.
I recall him talking about that ...
I think it is about time I downloaded a new version 7 of his ZEN stuff.
http://www.passdiy.com/pdf/zen-v7.pdf
:thumb:
I'll grind away just one more time :
In the PA world in the early eighties we all had just a couple of designs of amps and one paper they where all very similar and close to there original application notes for the output devices.
All had brochures quoting the same stuff +/- a little.
We all ended up choosing the ones with the higher rail voltage and most important was that we ended up putting on the top end. It was the gutless amp. Had the voltage but not enough power supply or enough output devices in parallel. It was smaller and lighter. A good balance of cost and performance.
There was a lower wattage version of the gutsy amp but this wasn't used as it didn't have the volts BUT did return the same power figures into 2 ohms as the above amp.
Given you have the current for the application it seems that the volts directly relates to headroom/ level.
During recording a mic-pre amp has headroom. How much headroom is required ?
Should the following line stages have the same headroom ?
Should the amp/speaker system have the same headroom ?
