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Hoffman Amps Forum image Author Topic: VVR : bad experience ?  (Read 2584 times)

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Offline Colas LeGrippa

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VVR : bad experience ?
« on: July 22, 2012, 07:03:56 am »
VVR circuit appears to me not to be  a reliable circuit, twice it failed though I have screwed the mosfet on a heat sink with an appropriate isolator from gnd. Symptons are just like a bad filter cap or bad power tube would do: loss of power and harsh sound. Did you guys having trouble with VVR's ?
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Offline tubenit

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Re: VVR : bad experience ?
« Reply #1 on: July 22, 2012, 07:43:33 am »
Quote
Did you guys having trouble with VVR's


Used it on 4 different amps.  No issues.

With respect, Tubenit

Offline Colas LeGrippa

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Re: VVR : bad experience ?
« Reply #2 on: July 22, 2012, 10:23:05 am »
these mosfet ( NTE2973) can stand 900V so way over needed , after the data sheet, the only problem I see is the static electricity that they are sensitive to, maybe I did something wrong in handling them

Colas
Don't miss the Woodstock experience : ''FORTY YEARS AFTER'' at Club Soda,  in Montreal, august the 17th and 18th and october the 27th. Fifteen musicians onstage.  AWESOME !
P.S.: call me Alvin.

Offline Ed_Chambley

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Re: VVR : bad experience ?
« Reply #3 on: July 22, 2012, 11:10:33 am »
I have tried them in many different amps.  I think the idea is great.  Never had any problems with the actual circuit, but I also have never really liked the result.  I have tried scaling everything and just the power section, but it ends up sounding like I am simply over-driving the preamp and when everything is scaled the tone-stack changes dramatically.  It is probably just the way or amp I have put them in.  I have never tried one on a amp less than 40 watts.

Offline The_Gaz

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Re: VVR : bad experience ?
« Reply #4 on: July 23, 2012, 01:06:57 am »
I've found it reliable, but only tried it in 30W amps. I think it sounds good, like anything, only to a certain point. What I find, however, is that it can convincingly take the volume down lower than a good master volume (PPIMV) or attenuator before sounding stupid.

 


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