Steel Guitar Strings
Strings & instruction for lap steel, Hawaiian & pedal steel guitars
http://SteelGuitarShopper.com
Ray Price Shuffles
Classic country shuffle styles for Band-in-a-Box, by BIAB guru Jim Baron.
http://steelguitarmusic.com

This Forum is CLOSED.
Go to bb.steelguitarforum.com to read and post new messages.


  The Steel Guitar Forum
  Electronics
  MosValve 500 Schematic

Post New Topic  
your profile | join | preferences | help | search

next newest topic | next oldest topic
Author Topic:   MosValve 500 Schematic
Jack Stoner
Sysop

From: Inverness, Florida

posted 05 January 2001 05:14 AM     profile     
Does anyone have a schematic for this amp? The other thread on Peavey amp pop makes me want to look at he MosValve 500 schematic as the MosValve does not "pop" when turned on or off.

Blake has pretty much isolated the pop (inherent in the Nashville 400 amp) to the power amp section of the Nashville so it would be interesting to see what MosValve is doing, or not doing, that prevents the pop.

Steve Feldman
Member

From: Millbury, MA USA

posted 05 January 2001 10:46 AM     profile     
Jack - Steve Bishop is the go to guy at Tubeworks for that stuff. He's a pretty good fella - you might want to give him a call.
Olli Haavisto
Member

From: Jarvenpaa,Finland

posted 05 January 2001 01:21 PM     profile     
I think many better quality power amps,such as the MosValve,use a relay that mutes the output to speakers until the amp is "settled".As to how this is accomplished I don`t have the vaguest idea..

------------------
Olli Haavisto
Polar steeler
Finland


Jim Smith
Member

From: Plano, TX, USA

posted 05 January 2001 08:51 PM     profile     
I think that must be a fairly common circuit. Both my Boss GX-700 and Digitech RPM-1 go through a "warm up" stage before they will produce any output, perhaps for the same reason of not spiking (popping) the circuits.
Robert Parent
Member

From: Savage, MN

posted 06 January 2001 05:19 AM     profile     
A while back I owned a Tubeworks Blue Tube II and needed a schematic. I just called them and they sent a copy free of charge.

I also purchased a new Tubeworks 1160 power amp that 'popped' when turning it on. I was not happy with the 'popping' noise and the roar of the fan so I sent it to the factory for repair. They returned it telling me that it was normal but did install a somewhat quiet fan. I still was not happy with the noise so I sold the amp even tho it was a very nice sounding unit. Currently I have a Roland GP100 and a Stewart PA100B and every thing is quiet like it should be. The Roland unit is very nice if you guys are looking for a one rack unit that does everything.

Jim Smith
Member

From: Plano, TX, USA

posted 06 January 2001 09:07 AM     profile     
The Stewart World 1.2 power amp has a sticker on top to remind you that it takes up to one minute after turning on the unit before any signal would be output, again I assume to keep from popping and spiking the circuitry.
Jack Stoner
Sysop

From: Inverness, Florida

posted 10 January 2001 06:27 AM     profile     
I got a (barely readable) copy of the MosValve 500 schematic. There is a relay on the output, which explains why there is no power on or off "pop".

The relay disconnects the power amp outputs from the speaker jacks. There is a sensing circuit associated with the relay but the schematic is so bad I can't make out a lot of the components.

All times are Pacific (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  
Hop to:

Contact Us | The Pedal Steel Pages

Note: Messages not explicitly copyrighted are in the Public Domain.

Powered by Infopop www.infopop.com © 2000
Ultimate Bulletin Board 5.46

Our mailing address is:
The Steel Guitar Forum
148 South Cloverdale Blvd.
Cloverdale, CA 95425 USA

Support the Forum