Amp/Preamp Asylum Looking for a new Amp or Preamp? If you're after tubes, post over here.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Amp/Preamp Asylum ]

---

[ Alert Moderator ]

---

RE: That's a common idea but rare in practice!

Posted by John Elison (A) on January 19, 2015 at 14:50:46

In Reply to: That's a common idea but rare in practice! posted by Ralph on January 19, 2015 at 13:22:41:

Well, I didn't know that. I was basing this idea on several other posts I've read where people talked about a fully balanced power amplifier. So, you say it is very uncommon to have a fully balanced power amplifier? I do know that when stereo amplifiers are bridged to produce a mono amplifier of greater power, they basically operate like a fully balanced amplifier with a phase inverted signal on one speaker lead and the in-phase signal on the other. I just thought that perhaps there were fully balanced amplifiers designed that way, too.

I do know that some preamplifiers are fully balanced from input to output because I own one. My Pass Labs X1 preamp is fully balanced with four discrete signal paths from input to output -- two for each stereo channel. Most of my components are balanced but one of my two turntables uses an unbalanced phono stage, which is connected to one of my preamp's unbalanced inputs. The problem with the unbalanced inputs is that they send a signal only to Pin 2 on the output XLR. My X1 also has a balanced tape loop, which receives a signal only on Pin 2 from the unbalanced inputs. I have a TASCAM DA-3000 DSD recorder connected into the balanced tape loop and I recently discovered that when I make a recording from my unbalance phono stage, the loud passages are severely clipped yet the meters do not indicate a problem. In fact, I was unable to even get the meters to go into the red. Apparently, when I turned up the input level control on my TASCAM DA-3000, it actually clipped the input amplifier on Pin 2 because there was no signal on Pin 3 of the XLR. I now know that I can record LPs only from my other turntable with its balanced phono stage.

I suppose I could get around this problem by connecting my other phono stage directly to the TASCAM DA-3000's unbalanced inputs, but it is really not a concern since my other turntable sounds better for making recordings anyway.

Best regards,
John Elison

This post is made possible by the generous support of people like you and our sponsors:

Parts Connexion

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---