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The Upgrade Company

+1 269-352-7609

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 (6) of David J. Schulte's patents




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The Upgrade Company, AudioVisual Equipment  Dealers, Harbor Springs, MI 











Contact Info

The Upgrade Company

+1 269-352-7609

This email address is being protected from spambots. You need JavaScript enabled to view it.

 (5) of David J. Schulte's patents

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+ 30 Day In Home 100% Refund Period

+ 5 Year Parts & Labor Warranty with Every Signature Edition Upgrade

+ 100% GUARANTEED to beat ANYTHING else on the market!


Nothing we sell ever comes back.  

We don't even have to advertise.  Once our clients experience for themselves the extreme high performance & "bang for the buck" we deliver, they keep coming back as funds permit.  

The Upgrade Company would not continue to be A+ rated on the nationwide BBB algorithm month after month unless we were delivering on our promises.

Please call +1 269-352-7609 to place order

Gryphon Testimonials

Unsolicited Customer Testimonials - Every client has paid The Upgrade Company LLC in full.   No kickbacks, no commissions, no fees of any kind for recommending our products and services.


Gryphon Callisto 2200 Integrated Amplifier Upgrade

Let me start by saying that I had researched getting mods done on my DV60 and was already to ship the Esoteric to The Upgrade Company based on their tremendous customer reviews... but fate stepped in... My much loved Gryphon Callisto 2200 integrated amp developed a noise in the volume one seemed to want to work on it but Dave said no problem, he went on to tell me he had worked on Gryphon's before with great success so, off it went to MI.  A few weeks later I got it back... Dave said it would need to be run in for a while but I could not wait... so, I plugged it in and started to listen... immediate difference in upper register and sound stage ... but yes the bass was congested... so I left it on over the next week before I did any more serious listening...When I went back to check it out OMG what a difference, the bass was DA Bomb.. so tuneful and melodic... I could make out the attack and pitch no matter who low the frequency, even with syn. bass... I've never said this before but alas it (syn. bass) actually could be not only tuneful but musical as well.  I also noted much cleaner transients as well as a large increase in sound stage depth. The amp which I had thought was about as good as it gets in pitch, flow, detail, sound staging, bass, and musicality took on a whole new break this down further I have listed the changes that I noticed in my system since getting it back, in order of magnitude (greatest to least), but I do want to say that all of the changes were important and easily discernable:

  1. Bass ... oh so clean and sweet with no overhang.
  2. Detail ... if you like layers of sound here it is. 
  3. Sound stage ... deeper to a great extent and somewhat wider. 
  4. Mids and highs ... much less glare more music. 
  5. Overall musicality ... greatly enhanced.

In conclusion, I liked working with Dave very much and got the feeling his is a labor of love...But as they say the proofs in the pudding... I am sending my esoteric DV60 to Dave to work his magic on (he says that this will make an even greater difference... ) can't wait to check out what this will do... and when that comes back I'm sending him my Blu Ray player so that I can attempt to reach video nirvana.  I don't believe that I'm given to overstatement, the changes were really that significant.

Dave thanks for your great work!!!

Vern, Quincy, Massechusettes retired music teacher and composer

Vern now has an Upgrade Co., upgraded McIntosh MVP-871 Universal player and upgraded Samsung 6900 Bluray player instead of the Esoteric DV60 we recommended the McIntosh 871 over.

Page information last updated: 20/04/2017

Disclaimer: We believe but do not guarantee that the information on this website is correct at the time of publication.

Our Clients Say...

November 2019

Dr. Ronald Stroud MD, Alabama

October 2019

Dr John Read
Jim Wojno
Jim Wojno
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