Musical Fidelity A300 mod by Tube Research Labs

Just a few comments on my MF A300 integrated amp which I had recently modded by Tube Research Labs (TRL).

I had just decided to upgrade my source and was searching around for a possible replacement or mod upgrade to my MF A300 integrated which I have had for a couple years.

The MF A300 is very nice unit which has given me much enjoyment. I had already had Tube Research Labs mod two digital units for me, and inquired with them about modding the MF A300. TRL is well known for their very high end SOTA custom preamps and amps and they agreed to see what enhancements might be possible for my modest little amp.

The fee for this is their standard $550 which they charge for modding digital units, transports, DACs, etc.

When I got the unit back after some initial break in, I made some notes and then asked Paul and Brian at TRL what changes they thought were made from their mod.

Both said almost the same thing that I now heard and had written in my notes-
Brian felt that the amp "had a very high noise floor and some glare".
Paul stated they attempted to remove "transistor artifacts" which creates an edginess to the sound and removing the noise allows a more 3D like soundstage.

Anyway, my notes started out with "Amp is much quieter now and sound is much smoother"... "Soundstage is much better now front to back".

With the lowered noise floor I am able to hear more information on familiar recordings and the instrument and player spacing and placement was much improved.
Much of the previous harshness I would get on some overly hot digital recordings was gone.

Anyway, after about 200 hours of break in, I would state that this amp is quite a performer now. Another benefit for me is that I use a dedicated tube phono stage (Hagerman Cornet) which uses one of the line in inputs on the MF A300. My Turntable front end is now also improved quite a bit.

Just wanted folks to know about how this worked out for me and it might be worth looking into if you like your present amp, but would like more performance out of it for what I feel is a decent price.

It is very difficult in my opinion to figure out an upgrade path (and matching) with an amp and preamp setup so improving an already decent integrated amp that I liked has worked out well for me.

TRL was quite impressed with the performance gains with the MF A300. Not quite in the class of their new ST-225 225 watt integrated amp, but that of course is a $5500 amp. Maybe someday on that one for me.. :)


When talking to Paul about the Alesis he explained that major improvements could only be made on the digital side and that they could not do the things that they would normally like on the analogue side as the board in the Alesis prevented it. He did say that they made the analogue outputs at the very least listenable. However, Michael Framer raves about this unit in stereophile and he uses the stock unit. Go figure.

One of the things I like about TRL is that they are in the very high end market. So when Paul says my Alesis used as a transport could stack up against the big MBL and CEC transports I believe him. Take into account that these guys also do work for companies like Intel and some of the R&D from that work can be used in their audio line.

If they can take $550 of mine and make the sound quality of my Cary one quarter of that which is exhibited by their top of the line amp ($125k) I'd be thrilled.

Well, they certainly have an incredibly wide range of experience to bring to bear to their work. It is also good to deal with folks that are very ethical and nice people.

I am guessing that Paul or Brian has mentioned their new ST-225 (225 wattx2) integrated amp they are coming out with.

I have a friend who is going to try it out with his Soundlabs. I may have the ST 225 visit my house for a day or two :)
TRL is quite excited about this venture into pure solid state.

Yes, they know pretty much everything that is out there and voice their units and mods to their own very high end reference units.
I am pretty confident that my MF A300 is now getting every ounce of performance out of it.
I am considering going your route MF a300 TRL modded unit. I currently have TAD-150 Tube Pre and TAD-60 Power - sound is amazing, rich, detailed, extended on top and bottom, musical. I have a baby and family who would like to use the unit provided it is simple.

My question and concerns is how much of tube richness would I miss going TRL modded MF a300? Would I gain anything musically?

I have TRL modded Sony 2000 ES SACD, it is quite a performer - I think it out performed Arcam 192 and Belcando DAC2 for me in my truly humble system. Currently using Von Schweikert VR1 monitors with sub, planning to upgrade to super revealing Tyler Acoustics.


I would call TRL and try and connect with Brian Weitzel whom you probably know already.
He really took a major interest in the transformation of the MF A300 unit. He obviously has a lot more experience than me in assessing amplifier character and quality, and of course TRL does state of the art tube (and now solid state units). He might be able to better answer your question about how it compares to the tube richness sound you prefer.

I would say that the sound is very neutral. Not dry, not lush. Very detailed, extended, and very very very low noise floor. The solid state glare was almost completely removed and in combination with my TRL Marantz SA14 (see my signature for complete system), the sound is almost devoid of any digital glare or solid state edge.

I would call the sound as leaning slightly toward warm, but not rich. I have ACI Jaguars which have a neutral and very slightly warm sound so system synergy comes into play.

Good luck. I am very happy with my MF A300 unit. It is very musical to my ears.