Jeff Rowland Model 7 & Model 5 Upgrade


This is my first, and long overdue, post on the forum boards so please bear with me. Wanted to let everyone know that there is a substantial upgrade available for owners of the JRDG Model 7 and Model 5 amplifiers.

Briefly, I purchased my Model 7's a little more than 3 years ago and was amazed at the sound. Then one night one of the amps died. Basically something went very wrong inside and it became so hot you could not touch it. Yes, these amps will run quite warm normally, but this was smoking hot.

Next day spoke with Jeff directly about the amps and after some fact checking and trouble shooting we discussed the possiblity of upgrading the amps. This was something he had been wanting to do for the Model 7 and Model 5 amps for some time. We discussed ICE technology, as this was the time of the TAS review, and I also had long discussions with the audio store where I had made most of my purchases. After some considerable thought decided to pull the trigger. Shipped them off to Colorado, in the original crates, and waited for their return.

In my discussions with Jeff we decided to leave the power transformers in them to filter the ac and Jeff basically completely gutted the amps and put all new technology in them. I have before and after photos that I would be willing to share with anyone but do not know how to post them to this site. The whole process took about 4 plus months as these were the first amps to undergo the upgrade and Jeff had to create everything from scratch.

Finally got the amplifiers back around Christmas 2006. Jeff even called the day I brought them home to see what I thought, I informed him I was just in the process of unpacking them.

Now to the specifics. With the upgrade there is a 5 year warranty, they shed about 20 lbs. and now weigh in at a little more than 100 lbs each with balanced inputs. Power is conservately rated at 600 watts at 8 ohms, 1200 watts at 4 ohms. They are in a constant "on" mode and never get warm to the touch. Basically they are the new 501's in a Model 7 body.

Now to the sound. After a year of listening to them all I can say is Marvelous!!! I am not an audio writer but will try to convey the difference and improvements as best I can. In a word "Articulation". They have not lost their midrange warmth, but have improved upon it. It is more open, less tube sounding. Instruments are better defined, but not harsh or edgey. The soundstage is better delineated.

Part of the reason for not writing this sooner is because I was making numerous changes and upgrades to my system. It is now basically set for some time to come and consists of the following:

JRDG Coherence I Preamp (updated), Clearaudio Maximum Solution, Graham 2.3 tonearm, Benz Micro M2, Brinkman Phono amp, JVC XL1010 CD Player, Otari MX 5050 4 track R2R, Sonus Faber Guarneri Memento speakers, Siltech SQ110 interconnects with SATT, Siltech Power Cords, Siltech Emperor with SATT speaker cables.

I want to publicly thank Jeff Rowland for all of his help in this process, and apologize for not writing this sooner. It is extremely rare in todays business world to come across a company like JRDG, let alone its founder, designer, and owner to spend the kind of time he did on this project. It truely speaks for his passion of audio and improving his designs.

Finally, I am not an employee or in anyway associated/affiliated with the JRDG. I am just an audio enthusist like everyone else that visits this site and would highly recommend this upgrade to any owner of the Model 7 or Model 5 amplifiers.
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Showing 4 responses by 94968

Couln't agree with you more Sirspeedy. The whole process and communication with Jeff was, in my experience, unprecedented. Your comments about the sound are right on. The voicing of the whole system has been greatly improved, and it doesn't matter where you are in the house the realism of the sound is uncanny.
I originally purchased these amps for two reasons. Like yourself I like the sound of tubes and these amps, to my ears, and the reviews that they had received, came closest to it in a solid state design. I wanted that sound without worrying about the availability of tubes, or of changing tubes. The reason for this is that I tend to keep things for a very long time. Economics and the spouse factor preclude me from changing components on a frequent basis.

The change in sound as best as I can describe it is that the warmth of the original tended to colour or muddle the sound. With the upgrade the sound is clearer, more delineated. Again the best word to describe it is articulation. Instruments are better defined but not with an edgy sound. On my system stringed instruments and acoustic guitar sound more natural. Having played violin for a number of years I am sensitive to what they should sound like.

I also prefer live recorded music as opposed to studio recordings. Since the upgrade I have had many more moments of being startled by the music into thinking you are there or that the performer is in my room. Again, to my ears at least, the sound is not harsh or edgy but very natural with some warmth and great presence.

In my discussions with the audio store where I made most of my purchases we came to the decision that it would be best to leave the power transformer in the amps. We were concerned about the "digital" sound of ICE Power but believed the power transformer would act as a great filter for the AC.

So, in answer to your question, I don't believe I have lost the warmth of tubes, but have improved upon its inherent characteristics.
The answer to your question about the cost of the upgrade is multifaceted. Remember these were the first Model 7 amps to be upgraded by Jeff. In my discussions with him before the upgrade he wasn't sure what the total cost would be. He wasn't sure how much time it would take and wasn't sure what all would be involved. He personnally worked on them for about 4 months. He told me that he had to repeatedly go to the CNC department to refine and make new parts. This was a work in progress and would be the template for offering the upgrade to other customers. Obiviously if I had to pay for his time the cost would have been exorbitant. My understanding is that JRDG is now offering this upgrade for about $2,500. Considering what is involved and the sonic improvements, in my opinion it is worth the price.
Hello Guidocorona, Can't say for sure as to whether or not Jeff included that within the modification. I know that he was using the latest updates in ICE Technology within the modification. He may very well have included the power correction logic but I will have to ask him directly.