Archive of the former Yahoo!Groups mailing list: MOTM

OK, I got one of these ART Levelars as a possible cop-out to not building my
own DIY tube wave-squashing distortion module. I thought, well, if I
overdrive the thing, maybe it might be just the ticket. In that respect, I
am not impressed.

So, here is a review, of some of the aspects I evaluated. They in no way
dispute the usefulness thaty others have found for this device. However,
they do confirm it is NOT what I was looking for.

The good news:

This thing interfaces with MOTM 10 volt p-p signals wonderfully. The
compression works with 10 volt input and 10 volt volt output without
noticeable distortion. In fact, I pushed the input voltage up to 25 volts
p-p trying to overdrive the input of the Levelar. No such luck. Amazing.

As a compressor / limiter, it seems to do a reasonable job. However, the
controls leave a lot to be desired it you are looking for much "fast"
action. But for more slow gentle compression, it seems fine. And, the
input range for compression is VERY wide from -40 to +10 dB.

The bad news:

This is not in my opinion a really good device for that classic overdriven
sound. The only way I could get any serious distortion of the wave was to
turn the output control on the Levelar all the way up. Then the distrotion
of the waves had two significant problems for those desiring a tube
distortion sound:

1. The wave clipping was just that - clipping. No gentle bending like one
would expect when hitting the non linear ends of a tubes characteristic
curve. It was much more harsh. Looking at it on the scope it resembled
hitting the rail on an op or something. Quite abrupt.

2. DC offset. For some reason, there is significant DC offset (almost a
volt) internal to the Levelar. Therfore, when one does start getting
distortion from clipping, it is only on the positive going 1/2 of the cycle.
Even with 10 volt input, I could only get distortion on one side. Now, with
the 25 volt input, I got lots of distortion (but again, from the output
stage, not from being overdriven by the input.

This review is not intended to dispute any of the fine thing others have
said about this unit. For $79 it offers a wide range of compression options
including balanced ins and outs. However, for gentle tube distortion, it is
the wrong tool IMHO.

So, there will still be a stooge designed tube distortion DIY circuit. It
is about 4th thing on my list-of-stuff I want to mess with. I am planning
to try to adhear to the MOTM format with all of the high voltage parts of
the circuit enclosed to keep it safe. I am planning the power supply to be
a AC style wall wart.

Larry Hendry
(I am old enough to have studied tubes in school. Trouble is I forgot most
of it.)