Contact Info

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

Esoteric & EMM Labs



Ed Momkus' take on
The Upgrade Company-modified Esoteric P70 CD transport/D-70 DAC digital system
(and a note on a modded EMM Labs CDSA SE)
“Get on the phone or computer and call or email David Schulte right now!”
December 2008

The Upgrade Company
1222 Walkabout Lane
Harbor Springs, MI 49740
Tel. 231-242-0946
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

See Momkus' Online Review


Well – not really – I was just looking for a cute subtitle. I’ve never met David Schulte, but I’ve spoken to him on the phone and corresponded via email.

When you talk to David on the phone, it becomes evident that you are speaking with a sincere and earnest man who has a passion for taking good audio equipment and making it sound better. However, if I hadn’t previously spoken to him over the phone and only communicated via a few emails, I probably would have imagined David Schulte to look like Einstein, but with the crazed look and maniacal laugh of a demented audiophile genius. After all, who else would send you an email at 2:00 AM to let you know that the mods are done and that the modified equipment is being cooked in anticipation of shipment in a day or two?  I’m sure that the engineers over at Esoteric, Mark Levinson, Krell, Acoustic Research, and the other audiophile manufacturers are dedicated, hard-working music lovers who work late when necessary, but not at 2:00 AM….


I have had the Esoteric P-70 transport and D-70 DAC for three and a half years now. The pair together was Esoteric’s “statement” redbook digital five years ago. About fourteen months ago, I began to get the itch to upgrade to an SACD player. However, even though I’d purchased many hybrid SACDs under the assumption that I would one day purchase an SACD player, I had yet to hear an SACD player that sounded better playing redbook than the P-70/D-70. Moreover, I discovered that the P-70/D-70 combo often sounded as good or better than the SACD layer of those hybrid discs. This included several good SACD players (such as the Music Hall Maverick and a Marantz DV8300) and even some top-tier players (such as the EMM Labs CDSA SE player – more on this later). Not content to simply wait for someone to make something clearly better, I set out on a search for potential mods.

Modificosa Nervosa

Once I started seriously thinking about modding my Esoteric P-70/D-70 combo, I also started to research various “mod shops” and their philosophies. The first thing I discovered was that no one had attempted to mod the Esoteric P-70 or D-70. This made me very nervous.
If I owned a Lamborghini Diablo and wanted to improve horsepower and handling, I would sure as hell want to have it done by someone who had done it before. Alas, I was going to have to trust someone to do a good job the first time. Given the relatively unique technology used in the P-70/D-70, I wasn’t comfortable with anyone who was going to radically change the guts of the units, after all I liked the P-70/D/70 and was attracted to The Upgrade Company/Dave Schulte’s philosophy of substituting better parts. I also saw that David had modded many other Esoteric products and I figured that his experience with those other Esoteric products would help. Finally, I’d come across the names of The Upgrade Company and David Schulte in the past when reading reviews of various mods, and the comments were very positive.

Mod One and Mod Two

I decided to “interview” David and exchanged some emails and spoke with him on the phone. He was very confident and reassuring, but I just couldn’t pull the trigger. Months went by while I continued to avoid making a decision. Finally, in March of 2007, I took a deep breath and sent the Esoteric pair to David along with $3,000 ($1500 for each unit). He got them on March 20th and shipped them back to me on March 26th. I reassembled my system and deliberately avoided listening for 24 hours.

When I finally sat down for some serious listening, I could immediately tell that the performers were larger and that the soundstage was deeper and more layered. This is unusual in my experience. In the past, “larger” performers invariably meant a more forward soundstage perspective. It was the first time that I had this experience when upgrading any component. I was quite satisfied with the value I had received, since added soundstage depth had been one of my primary goals in getting the units modded.

Two weeks later, I received an email from Dave Schulte which surprised me.

First, he had liked the Esoteric P-70/D-70 system so much that he went out and bought one. Second, he had been playing around with his new P-70/D-70 and had found a whole new series of mods that would elevate the combo to yet another level. Finally, he said that if I would just send the units back to him again he would perform these additional mods at the parts’ cost and not charge me for the labor. I was very impressed with Dave’s offer, but I had some downstream components I had in for review and couldn’t send the Esoteric combo back just then. “Besides”, I thought, “how much more improvement can you squeeze out from an already cream-of-the-crop component?” I liked what he had done and was reluctant to part with my babies a second time.

Three more months went by, but Dave didn’t give up. He again reiterated his offer to do the additional mods for just the parts’ cost. Finally, in July I gave in and sent the P-70/D-70 back to The Upgrade Company right before leaving on vacation. As before, David Schulte got the upgrades done promptly, but he also called and asked me if I’d also like to get the combo’s fuses replaced and upgraded with Hi-Fi Tuning fuses. I previously had great success with upgrading my amp fuses and would have also upgraded the fuses in the Esoteric combo, but they were located internally, so that you had to disassemble the units to replace them. I told him to go ahead.

Let’s go Live!

Let’s get to it. The Esoteric P-70 and D-70 took a few weeks to fully break in the new components, but the change was immediately evident. The improvements I noted before were much more obvious. First, the soundstage was even deeper and more layered. Second, the performers were not just larger, but they sounded more natural and created the impression of being more fleshed out.

In addition, and quite incredibly, both the lower bass and the upper treble became more extended and more detailed. I was particularly surprised by the improvement in bass, because the Esoteric P-70/D-70 was particularly good at rendering bass – in fact, the best of all the players I’ve heard.

All of these individual improvements stood on their own, but the real benefit was their cumulative effect. I had never heard, or should I say felt, an all-digital/solid state system to sound so immediate and “real”. I’m not saying that the modified Esoteric P-70/D-70 sounded “rich” (it did not, nor did I want it to). I’m not saying that it would sound equally “real” in a different system. I am saying that in my system, the modified Esoteric P-70/D-70 was finely balanced on that razor-sharp dividing line between richness and accuracy and produced music the way I hear it when it’s live in an excellent acoustic venue.

An encore with a CDSA

This experience was plenty to convince me of The Upgrade Company’s high quality work, but I should also tell you that Dave sent me an email seven months ago stating that he had performed mods to a EMM Labs CDSA SE, and if I would know anyone who might be in the market for one.

As it turned out, I had just been asked by a client to recommend a top-tier player. I had actually told him that he’d love the CDSA for classical, but that in my prior audition in my system, he’d be disappointed with its performance on rock and roll. He loves bass; in my opinion, the CDSA I’d compared to my P-70/D-70 just didn’t have it. Dave’s email specifically stated that he had corrected the CDSE’s “light” bass, so I called my client and told him that if Dave says it, it’s a good risk.

My client’s listening room was still under construction, so he asked me to hold the CDSA for him for two months. When I put the unit into my system, I could immediately hear the CDSA’s renowned clarity and airiness, but now the bass was visceral without losing any PRAT or dynamics. More evidence of the value a knowledgeable “modder” can add to your system.


Lo and behold, I received another email from Dave last week indicating that he’s found another mod that he says will upgrade performance of the P-70/D-70 another 25%! Based on my past experience, how can I not do it? I’ll have to wait a month or so to complete evaluation of speakers I’m reviewing, but I’m definitely going to do it.

Based on this short review, you’d probably guess that I recommend The Upgrade Company and David Schulte for your upgrade needs. Well, you’d be right – and in spades! My experience was very positive. If you’ve got any of the components that is on Dave’s mod list (check his website and email him), send them to him for some amazing improvements. If, like me, you have something he’s never modded before, send it to him with confidence. You will not be sorry.

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