DAN Wright, the “Wright” in ModWright Instruments Inc, and company president and founder, talks about his first integrated amplifier, the KWI 200:
Tell us about the design brief of the KWI 200.
The KWI 200 is a pure solid state, 200W Mosfet output, discrete JET/Bipolar input design, featuring Alan Kimmel’s ‘Solid State Music Stage’. The amplifier section inputs are Lundahl transformer input coupled and fully differential. The entire design is direct-coupled, with zero global negative feedback and no coupling capacitors in the signal path.
Volume control is by a digitally-controlled analogue stepped attenuator, which provides better sonics than a standard potentiometer and control as fine as 0.5dB per step.
The KWI 200 was designed to be as fully integrated and upgradeable as possible. It has both XLR and RCA inputs, preamp inputs (via HTBP – Bypass Input) and preamp outputs, remote trigger outputs, optional phono and DAC (24/192 USB/RCA fully asynchronous), and virtually all controls (excepting the HTBP – Bypass function) are via remote.
What templates are its preamp and power amp sections based on respectively?
The preamp section incorporates the Solid State Music Stage and variable gain, digitally-controlled, analogue stepped attenuator volume control. The power amp section is a ‘Source Follower’ design, using Mosfet output devices, with zero negative feedback.
Why did you settle on solid state, rather than tube circuitry for the preamp stage?
To be honest, because of cost. I wanted to release a high-power integrated at a price that was attainable by many, and that was a no-compromise design, sonically. Adding a tube input stage would have added considerable cost and I decided to design this product at a later date, based on the reception of the KWI 200.
I should note that because the KWI 200 has a preamp input, actually labelled HTBP or Home Theater Bypass, a tube preamp can be used with the KWI 200. In this configuration, the KWI 200 would act strictly as an amplifier, with the preamp feeding the amp’s input stage directly, bypassing its own preamp stage and volume control.
Some companies start off with an integrated amp in their line-up before moving on make separate components, while ModWright took the “design down” route. Is this a better approach – what are your thoughts?
We actually started with tube preamps and then added amplifiers to our line. I prefer tube preamps with solid state amps for separates.
Our first (p0wer) amp to be released was the KWA 150 (now available as the KWA 150 Signature Edition), for which we have received numerous awards, including a Golden Ear Award from The Absolute Sound.
When Alan Kimmel (creator of the vacuum tube Mu stage) and I set out to design the first ModWright amp, we wanted it to be a statement piece and for people to take notice of ModWright Instruments as an amplifier manufacturer also. As to whether our approach, by logical evolution, is better than starting with an integrated amp, is a difficult one. I would say, that I believe it is MOST important to get the signal right from the source, then the preamp and finally the amp.
No matter how good the speaker and cabling, it can only reproduce what the amp provides. Also, because equipment cannot ADD musical resolution or content, but can only do the best possible job of recreating the original recording, it is important for every piece of equipment to be of the highest calibre, beginning with the source, in my opinion.
Phono and DAC (RCA and USB) options are available for the KWI 200 – given the proliferation of computer audio systems among audiophiles now and that vinyl is holding its ground, why were these not part of the standard package? After all, the KWI 200 is touted as a one-box solution.
It is for the same reason that we make the metal remote, a (US)$200 option. I wanted to produce a US$5,000 integrated. For those who want the metal remote, DAC and/or phono, they may elect for those options, but are not forced to purchase all options that they may not need.
I believe in offering clear and attractive upgrade paths for all of our products. If I were to have offered both DAC and Phono and keep to our intended price, then other areas of the design would have been compromised, in addition to the phono and DAC stages themselves. This was not a compromise I ever want to make.
Was the Theater Bypass mode necessary for the amp?
It is necessary for those who choose to integrate a two-channel audio system into a multi-channel home theatre system. This is quite common in the U.S.
The other function of the Theater Bypass, is to allow for a preamp INPUT as well as preamp OUTPUT. Again, the idea was to provide as many functions as possible, in order to make the unit both fully integrated and flexible enough to be used in a variety of different systems.
Although there is a set of XRL inputs, this is not a balanced design, right?
That is correct. The preamp stage is single-ended. We added the XLR inputs only as a convenience to those who have balanced cables. We have both XLR inputs and outputs, actually added after many of our distributors requested it. Again, as in the LS 100 (preamp), being a single-ended design, they are wired single ended, not balanced.
For a company that made its name modding digital players and continues to hold its own in this area, ModWright has yet to offer one of its own. Can we expect something along these lines soon – at least a standalone DAC with USB – in the very near future?
A standalone DAC yes, but not a CD player. The design of our standalone DAC is in process, but I do not have a date for its completion yet. I can only say that we will release it when I am satisfied with the design. It will be similar to, but advanced beyond, the design of our internal DAC option for the LS 100 and KWI 200.
I will not build a CD player, because technology and “disc” formats have changed so rapidly over the past decade, that I don’t want to invest capital into a design that may be obsolete by the time it is released. I believe that a high-quality DAC will always be in demand, and of course with the move towards computer audio, USB inputs are also a must.
