Balanced Audio Technology Rex II Amplifier

bonzo75

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Feb 26, 2014
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I agree, you need a couple of amps, like micro (more than a couple) and Xv-1 do. But I think Ron ideologically wants to have one amp, one pair of speakers, one system.

In his case an SS and a push pull (or SET, if he fancies) will be ideal
 

Ron Resnick

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. . . I think Ron ideologically wants to have one amp, one pair of speakers, one system.

In his case an SS and a push pull (or SET, if he fancies) will be ideal

+1

I can totally see myself having two or three or even four amps for a period of time, but, eventually, I would keep only one and sell the rest.
 

cakeaudio

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Jun 8, 2012
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This is a very fair question!

I can't audition every interesting amplifier in the marketplace today. I have to narrow the field somehow. If I were looking at solid-state, for example, I would audition only Gryphon, Pass and Vitus.

I am a bit dogmatic about the electronics I want. I have never heard transistor amplifiers on Martin-Logan hybrid speakers and liked the sound. I have never cared for Magico loudspeakers until I heard the M3 and the S5 Mk. II powered by tubes. The sound of tubes works for me. It's a simple as that.

I might be very happy with the sound of Vitus solid-state amps. (Kedar assures me I would be, and a friend with Pendragons and now Kodos uses Vitus.) But if I wanted to go in a neutral sound direction I would just get CAT JL-7s.

PS: I preferred the sound of Jeremy's MBL 101E Mk. II system driven with the Class D Noble amplifiers over the top-of-the-line amps. I remain flummoxed over this preference on that system.



Hi Ron, I have a pair of BAT Rex II mono's and have the new Vitus SS-103 amplifier coming in a week. You are welcome to listen to them here or at your place - I am not that far away.

Ken Boyce - Cake Audio
 

Ron Resnick

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Dear Ken,

Thank you for writing!

Vitus Masterpiece monos were used by Dato' Danon Han on his and are now on his Kodos.

Could you please explain the circuit topology of the Rex II? I have read all of the BAT marketing literature and I do not understand it.

1) Is the Rex II biased into Class A? If Class A, is it Class A for all of its output or just a portion of the maximum output?

2) Is it a push-pull design?

Thank you!
 

awsmone

Well-Known Member
Apr 6, 2014
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Hi Ron

Looking at the fact they are using a stereo pair to convert to mono, they are two halves, so it’s bridged which may be parallel or series

6c33 to produce this sort of power output must go into AB, as most will only do 20 watts class A, so 80 Watts

To get 140 Watts ie 35 watts a tube it must go AB1,

A simulation I get 35watts per tube in p-p with 4% distortion at max output with 7.5 watts in Class A, ie 30 watts for 4 tubes in class A
 

Rocco I.

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Apr 26, 2012
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I've listened the combo BAT REX II (amp & preamp) drove the Burmester BA71 through eeffortlessly, astonishing level of dynamic, complete lack of grain, excellent level of timbral accuracy and very good capability to resolve the minutest details gives the last bit of realism to recorded music. In my humble opinion is a great combo.
 

cakeaudio

Well-Known Member
Jun 8, 2012
32
5
915
Southern California
Dear Ken,

Thank you for writing!

Vitus Masterpiece monos were used by Dato' Danon Han on his and are now on his Kodos.

Could you please explain the circuit topology of the Rex II? I have read all of the BAT marketing literature and I do not understand it.

1) Is the Rex II biased into Class A? If Class A, is it Class A for all of its output or just a portion of the maximum output?

2) Is it a push-pull design?

Thank you!

Ron,

The REX is heavily biased class AB, but those standard terms do not apply to it, as its tubes never go into cut-off, due to the unusual output bridge configuration.

It is not the traditional push-pull design. It is output bridge.

Ken
 

Rumpole

Active Member
Aug 26, 2023
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Hi Ron, I have a pair of BAT Rex II mono's and have the new Vitus SS-103 amplifier coming in a week. You are welcome to listen to them here or at your place - I am not that far away.

Ken Boyce - Cake Audio

Very old thread, I know, but I'm curious if you ever did this comparison, or if others have an opinion on the BAT Rex II or III? It's difficult to find reviews of these. I've always been interested in 6C33C amps. I briefly had a pair of Supratek monoblock amps that used 6C33C tubes, and they were amazing, until one died. I bought a box of 50 spare 6C33C tubes 20 years ago, anticipating getting a new 6C33C amp, but have not done it yet.

After having problems with various tube amps, I decided to simplify with solid state a few years ago, but the idea of a 6C33C amp keeps nagging at me. :) I would use them with either YG Hailey 2.2 or SF Electa Amator III speakers. I don't think the Lamm amps would have enough power, so I've been considering BAT.

These would be my winter amps, so heat would not be a concern.
 

Ron Resnick

Site Co-Owner, Administrator
Jan 24, 2015
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