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Topic: Nashville 1000....is this correct??? |
Kev Conlon
From:
Leeds, England
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Posted 12 Apr 2013 12:33 pm |
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The amp....Nashville 1000....has not cut out for several hours now, but while monitoring the situation, I've noticed the following....
When left to 'idle'......with Pre-gain and Master gain set at around 2.5.....there is a noticeable difference in temperatures of two large heat sinks at rear of the amp! The sink nearer the mains transformer warms up considerably after 30 mins, whereas the other remains totally cold!!
Is this intentional, and relating to a design feature....or is only one 'half' of the power amp actually working??
Would appreciate any observations from folks out there with Nashville 1000's
Many thanks...... |
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Mike Wheeler
From:
Delaware, Ohio, USA
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Posted 12 Apr 2013 5:37 pm
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You need to take the amp to a tech. Both sides should be about the same temp. I wouldn't even use it till it's checked out. It sounds like the two sides aren't balanced, or maybe the power supply rails aren't equal but opposite values.
Maybe it just needs a cap job. Can't really say, but I'd get it to a tech.
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Best regards,
Mike |
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Kev Conlon
From:
Leeds, England
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Posted 12 Apr 2013 11:31 pm
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| Mike Wheeler wrote: |
| ................ but I'd get it to a tech. |
Thanks......will be going along that line I think!!
Circuit diagram would be nice to have.
Anyone know where I'll find it?
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Jack Stoner
From:
Kansas City, MO
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Posted 13 Apr 2013 2:12 am
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| The NV1000 has a "digital" power amp section. That is the type used by some amp designs. e.g. the Peavey DPC750/1000 power amps use a "digital" power amp section, the popular Gallien Kreuger MB200 amps are digital, etc. |
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Kev Conlon
From:
Leeds, England
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Posted 13 Apr 2013 2:23 am
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Hhhhmmm......not sure just what you're telling me there Jack  |
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Mike Wheeler
From:
Delaware, Ohio, USA
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Posted 13 Apr 2013 4:57 am
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Kev, you can call Peavey and ask for a copy of the schematic. They will email it to you for free. If you want a paper copy there's a small charge. 877-732-8391
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Best regards,
Mike |
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Jack Stoner
From:
Kansas City, MO
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Kev Conlon
From:
Leeds, England
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Posted 13 Apr 2013 9:49 am
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Well.....I've read as much of that as I can...with very little understanding I'm afraid to say
Suffice to say, I picked up the impression that Class D amps, like the 1000, generate little heat, by their very design!?
It may very well be that there is no fault in this respect.....the amp IS working after all!!... 
and it hasn't yet cut out after several hours powered ON... |
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Larry Bressington
From:
Nebraska
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Posted 13 Apr 2013 4:06 pm
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Kev, it sounds like one of the output transistor's is going into 'Thermal Shutdown' to protect itself, if it shut's off when it gets hot. Check for solder cracks around the Transistor pins in the circuit board, that is the most common heat issue area's ala warming up, cooling down.
1) Does it cool down when the amp is still on but NOT putting any signal through it?
2) Does it just get hot the minute you turn it on.
If it cools down, it's most likely right where i said. Solder issue's PCB are number 1 complaint.
If it get's hot immediately, a possible shorted output stage is possible, Mosfet's etc. However i have never opened one of those up, but most of the time it's something simple...Then check the reason why? Ohm out speaker etc. You will have a problem if you don't address this issue immediately.
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A.K.A Chappy. |
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Hucky Bruegger
From:
Switzerland
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Posted 13 Apr 2013 5:57 pm
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 you can stay cool.
on the nashville 1000 the two heathsinks are used for 2 different functions. looking from the backside:
the left one (near power socket and mains transformer) is cooling the switching power supply - 2 powermosfets and 4 diodes.
the right one is cooling the digital power amp - 2 powermosfets. the temperature of the two sides can be different based on the output power.
while the two heathsinks feel different temperature, your poweramp is not in a unbalanced mode. |
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Kev Conlon
From:
Leeds, England
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Posted 14 Apr 2013 1:33 am
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| Mike Wheeler wrote: |
| Kev, you can call Peavey and ask for a copy of the schematic........ |
Thanks Mike....e-mailed 'em....always worth having the circuit diagram!!
And thanks also to Larry....poor soldering or 'dry-joints' always a possible culprit on a 15 (ish) year old bit of kit!
| Hucky Bruegger wrote: |
you can stay cool....
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That's music to my ears..
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| ....on the nashville 1000 the two heathsinks are used for 2 different functions........... |
Phew!!....was hoping for a simple explanation here!!
Sorry if I may have 'over-egged the pudding' in my initial description. I was concerned about a difference in temperature between the 2 heat-sinks...but neither was actually hot
Thanks again to all!!!
Happy (ish!!) Chappy in the UK |
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Ken Byng
From:
Southampton, England
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Posted 15 Apr 2013 4:36 am
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Kevin
Hucky Bruegger is a good man, whose knowledge of Peavey amps is second to none. He helped me out no end when my Session 500 developed a fault in Zurich many years ago (1982). He loaned me a Nashville 400, and the difference in quality with the 2 amps was amazing. I ditched the 500 as soon as I got back to the UK thanks to Hucky. Saved a lot of weight and bulk with the upgrade to a NV 400.
Ken
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Show Pro D10 - amber (8+6), MSA D10 Legend XL Signature - redburst (9+6), Sho-Bud Pro 111 Custom (8+6), Emmons black Push-Pull D10 (8+5), Zum D10 (8x8), Hudson pedal resonator. Telonics TCA-500, Webb 614-E, |
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