Berning ZH-270 Replacement

With the exception of a small input DC blocking cap, the ZH-270 is DC coupled, so how is this possible with a output transformer ?? I tell you how, it's not !!
We've gone down this road time and time again, it's obvious it's beyond comprehension for most, but an OTL it is.

A person has the tendency to believe what they can understand and doubt what they don't and since this is a highly technical piece beyond anything ever made in audio, it leaves a lot of open endness for somewhat misguided debate.

And as always listen and compare for yourself, not everything is for everyone.

bpinder, why don't you contact Sonus Faber and see what they say, I don't know how much input Franco has anymore but he still owns a ZH-270 and the first introduction of the Stradivarius was done using the modest ZH-270, I think it was Fremer what visited Franco, look up the stereophile review.

It surprises me that the ZH-270 is strained at higher levels, have you played with the volume control.
There are several reasons why I am surprised but one mostly is that the ZH-270 does not act like most amps when pushed, because of the sophisticated auto bias, it senses when it's close to clipping and reduces power to the amp, this happens at a super fast rate up to thousands of times a second, so all that might be perceived is a slight reduction in dynamics.

One way to tell if you're reached close to output power is keep turning the amp up, it should react with very little difference in perceived volume, if there is a volume increase then it's elsewhere in your system.

These amps are used by so many manufacturers for designing it will surprise you, including the speakers mentioned here by jwmazar Chris Sommovigo's Stereolabs, what makes these amps great for this, is what makes it unforgiving for the average audiophile, they are not filters which is a limit of the typical design constraints, get it all right or this amp is going to tell the story.

Ever thought of just breaking down and going with an active pre!
the other option is we can talk you through a resistor/divider network design, that would drop the gain say 20-30db and sum both channels, then you can run that to the low level of the sub input.

pubul57, there were many factors that contributed to David's decision to stop making the ZH-270, which was in high demand and close to 3 years out of production still is, he gets about 2 inquires a day asking for a "last special ZH-270", just one more.

The problems are that there is components that has to be specially made for the ZH, some can only be made by a single specific manufacturer in Europe and then some can only be made by David, these component are only for the ZH and serve no other purpose in anything else in the world, tooling, minimum quantity, inflation cost, parts increases, so if you take into account that a ZH-270 has over a thousand parts, all this adds up quickly.

Dave had bought, what he thought was a lifetime supply of these parts for the ZH-270 but after a production run of 11 years, they ran out, in pricing out a new run of ZH-270's the cost would have made them close to $11K, also the chassis was homely and that needed updating, so his logical step was the Quadrature Z, a no holds barred statement.

Take heart though, there is trickle down technology from the Quadrature Z coming into a new 30 watt Stereo amp, called the ZH-230, new chassis, higher bias (closer to Class A), special new low loss material board, new impedance converter device with a fixed frequency of 500kH vs. 250kH for the Zh-270, lower distortion, higher bandwidth and some other unique abilities, price will be more than what the ZH-270 was but less than what a ZH-270 would have to be.

ZH-2100 100 watt per channel Stereo amp to follow next year.

As always, limited availably.