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Phase angle changes in amplifiers


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With a Vandertseen speaker maintaining the proper phase angle of the input, what about the changes to a signal as it goes through the amp?

My old tubed McIntosh MC240 was rated at 0 phase shift, plus or minus 6 degrees. (20hz to 20khz)

My Carver TFM 35x is rated at 0 phase shift, plus/minus 10 degrees.

 

Questions: Is this audible?  How do new amps compare?  Do they even list specs for this anymore? 

 

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@Richard Vandersteen the MC240 was perhaps the pinnacle of transformer design for both bandwidth and other effects. i don’t know the negative feedback db but it must be relatively low. I think sonic differences between the Carver and the Mac are most likely not due to differences in phase error.  My 240 images quite well , especially image depth. I use the Opus 3  Depth of Image test disc to assist in tgis assessment. Cool ? i copied RV to spur a weigh in from him….

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13 hours ago, GdnrBob said:

If anyone can point me to some not too technical resources regarding phase shift and phase shift with regards to impedance, I would appreciate it.

I have a limited understanding about it, but want to finally lock it down. 

B

Good point.  An amp changes the phase depending on frequency and impedance of the speakers. 

The BEST amp technically would be perfectly phase shift free, even with impedance changes in the speaker response curve.  

As far as tube versus solid state amps, I hear sonic differences in what I call the "signature" of the amp.   

My buddy just fully restored a 1962 Bogen DS265 tube amp for me.  I'm looking forward to hearing how it pairs up with various vintage speakers I have restored.  The output transformers are MASSIVE.  Bench tested at over 72 WPC, 20hz -20Khz.

 

Question for RV:  For the 2Ce Sig II, what output tap would be better to use, 4 or 8 ohm?   thanks.

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  • 2 weeks later...
On 11/23/2021 at 5:55 AM, DC-93 said:

With a Vandertseen speaker maintaining the proper phase angle of the input, what about the changes to a signal as it goes through the amp?

My old tubed McIntosh MC240 was rated at 0 phase shift, plus or minus 6 degrees. (20hz to 20khz)

My Carver TFM 35x is rated at 0 phase shift, plus/minus 10 degrees.

 

Questions: Is this audible?  How do new amps compare?  Do they even list specs for this anymore? 

 

This was only a factor with tube amps because it was used  as an indicator of the bandwidth of the output transformer.  It may be a factor today with class "D" amplifiers especially with DSP as some of them have steep filters on the output near 20KHz.  This narow bandwith with steep filters could cause significant phase shift. 

RV

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@DC-93the appropriate transformer tap to use is the one that sounds the  best.  Experiment and listen. I don’t listen very loudly here in the condo with Treo and a 40 wpc tube amp.  Something i learned from Roger Modjeski was to try the lowest tap that yields best sonics. This is called “ light loading “ and my understanding is the amp stays in class A longer….

Hope this helps !

Jim

Edited by TomicTime
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Loved his gear, that's for sure.  Too many folks are only able to hear what their local stores have or what a friend may have.  There is a ton of well engineered products for a fair cost at all price points.  I used to love putting together systems back in the day for 1k-2k.  That included cables (who even had special power cords back then), turntable and cart, an integrated and speakers with stands if needed.  

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