To modify or not to mod..... that is the question.

Bill, the short answer is yes. Basically you will get more from whatever cartridge you use, when you have an improved tonearm. But that does not mean that the cartridge is unimportant. A better cartridge will still sound better on an improved tonearm.

About the mods, I think that the OL arm mods are the best ones, because of the better coupling of the end-stub, compared to Expressimo. So get the OL arm mods, and maybe an Incognito wiring loom for your arm. The best part from Expressimo, is their Heavyweight counterweight, and I would definitely get that, and put it on the OL modded RB600. You'll also need a VTA adjusting collar, and either the OL or Expressimo is fine for that.

Once you get all this stuff put together, then set the VTF dial to 3 grams(which defeats the VTF spring-factory default), and use a stylus-force scale to set your VTF. This will improve the sound because the VTF spring adds a tonal coloration to the arm.

When you set the VTA, only tighten the big nut with your fingers to a "snug fit" and not real tight. You will find that fiddling around with the tightness level of this big nut, that you can get a better sound, when you find the "right" tightness level. Never use a wrench on this nut. That would make it way too tight, and will "deaden" the sound quality. Just "snug" by fingers is just about right.

Of course, then you will have to play around with VTA to get it just right after your cartridge breaks-in.

These things should really get you somewhere. They are good mods, but will add up to some money.

If you could get a phono section that would handle a low output MC cartridge, you could then get a Denon DL103R, which would really knock your socks off, for only $230. You'd need one with about 65db-70db of gain, as the Denon has only .27mv output. Quite low. It will sound significantly better than even the Dynavector 20X and will destroy the 10x4. It would be great on a modded RB600. This is the "cat's meow" of low priced MC cartridges. Of course, the 10x4 is no slouch, and would also be a nice sounding cartridge, but not in the league of the DL103R.

If you are really enjoying your analog, and it sounds like you are, then you are going to need to get into the low-output MC cartridges sooner or later. If you can get your phono stage where you can accept these cartridges, it will broaden your horizons for cartridge selection, and will allow you to use something like the DL103R, which will give absolutely terrific sound for very low money. I have used one for the last few months on my rig, and believe me, this is one helluva cartridge. At only $230, it really makes everything else look very overpriced. You would not be disappointed with this cartridge, I can guarantee that. I have now moved up to a Shelter 501 at $800, but that Denon is about the best thing I've heard under that price. The Shelter is better, but the character is very similar. For the money, I still think the Denon DL103R is the best value in all of cartridges today.

A cartridge like that in a modded RB600 would give stunning performance levels, and would actually exceed the capability of your TT. The P25 would be holding you back at that point. How does that grab you?

Now before you go out and spend your money on these mods, you need to consider that these mods will cost upwards of $600. You could sell your tonearm, and buy an Origin Live Silver Tonearm for only $790, and this tonearm will kill any modded RB600. If you could get $450 for your arm, and only then spend $340 cash, you could get world class tonearm performance for less cash outlay. Also, what is very cool for you is that the OL Silver will drop right into your Rega arm-hole, and plug-and-play, with no fiddling around. Then you don't have to send your arm out, or take it apart yourself, and risk screwing things up, and get better sound than it is possible to get from an RB600.

This is important to consider because the arm mods you may be considering will cost near what the OL Silver costs. There is no comparison in the performance between the two.

Think about this.

Inna, I agree that the P25 can be beaten by a Nottingham, but it is not very nice to refer to anyone's TT as a "toy".

Your statement about the TT being more important than the arm is very true. However, I diplomatically mentioned that if he made these arm upgrades, that the P25 would be holding him back, and would have to move to a different record deck.

I have no argument with your logic. But I think you could have worded it a bit nicer.

If you haven't heard the Denon DL103R, you really should listen to it. It is quite an overachiever at it's price range. I have witnessed it out-perform cartridges over 4 times its price. However, I do not recommend its use on a unipivot arm, as the compliance is much too stiff for them. It really needs the stability of a heavier gimbal-bearing arm to work properly.

Okay Bill, to answer your questions. The difference between a modded Rega RB600 and an OL Silver is quite large. Far, far more than the price difference. Whether you think it is worth the money is a personal decision, but to give you a guide, let's look at some things. First, an OL modded RB600 is not as good sounding as an OL modded RB250. Primarily because of the VTF spring on the 600. The modded 250 is the best sounding of all OL modded Rega arms. The OL Silver is about twice as good as the OL modded RB250.

Now this is all relative, because the Rega arms are already some of the better sounding arms available, and are good value before you even start modding. When you start with the mods, the 250 is the best one to mod, because it can come out at a higher performance level, than any of the other Rega arms, after modding. A modded 250, will sound better than a modded 900. The reasons for this are all explained on the OL website. A modded 250 is known as a "giant killer" arm, because it performs near the level of some of the best arms around, for alot less money. It is a great value for the dollar, and I by no means am knocking this modded arm. It is one of the better arms out there, and would be at home on a very high priced turntable, and sound great.

Now when we get to the OL Silver, we are in another category altogether. This arm was designed from the ground up to be better in all respects than a modded Rega arm. And it is. It gives performance at or above just about all of the top arms out there. It IS one of the top arms out there. So, you can choose, do you want "near" to the top arms, or do you want "one of the top arms".

Now getting to the Expressimo Audio mods, they are some good mods, and are very similar and close in performance to the OL mods. I would say that some people might not be able to tell the difference bewteen them. I think that the coupling of the OL end stub being minimal in contact with the arm tube, gives the OL stub an edge in performance over the Expressimo. Not alot. The Expressimo Heavyweight is definitely the counterweight to get, whether you get an OL end-stub or not. The Expressimo or OL VTA adjusters are about the same. The Cardas wiring in the Expressimo is probably a little better than the OL wiring. All-in-all, there is not alot of difference there. Both are good.

If your budget allows only $300 incremental spending, then maybe that points towards modding a little at a time. I'd do the VTA adjuster first, then the end-stub, then the wiring, then the Heavyweight.

About the cartridge and phono stage, if you have a high gain line stage that can add about 25db to the 53db of your phono stage, then you could use the Denon DL103R, without a transformer. Viridian pointed this out to me on another thread yesterday, that I was not considering the gain of the linestage, when I was calculating total phono gain. He was, of course, correct, and I am now mentioning it to you. If you can get a total of about 75db-80db out of your phono stage and preamp combined, you could get into the ballpark. You may have to turn up the volume a little higher to get normal SPL.

Now, getting back to your turntable, while Inna was less than diplomatic, he was actually correct in that you could get more performance increase by improving the table, than you can by improving the arm or cartridge. This is the case with ANY table, not just yours. It is an analog maxim. However, there is no rule that states that you cannot improve your arm, with the idea that eventually you will transfer it onto your next table upgrade. I think that this is what you are doing, and you will upgrade tables in the future, I'm sure. Because I can see you have the "fever" and you will want to improve in that area as well. In the meantime the P25 will serve as well as it can. Very few ever reach the level where no upgrading is possible.

Now to make a summation here, if I were in your position, with the money budgeted in $300 increments, I would first put my RB600 on the Audiogon, with a price tag of $495. If I could get it, or near it, I could then take my $300 cash and add it to what I got from the sale of the RB600, and order an OL Silver as fast as my hot little fingers could dial the phone. If I only could get $400 for the arm, I would skimp on lunch for a while and order an OL Silver anyway. If I couldn't get $400 for the arm, I'd mod it with whichever brand mods I liked best, in the order I mentioned above. Either that, or order an already completely modded OL or Expressimo RB250, by adding whatever I could get from the RB600 and cash difference.

Then when you get this done, you have to seriously start looking at turntables, as the next step. Any of these arms are beyond the P25. Not that they wouldn't be good on it, but they would be far more forthcoming with their possibilites of performance on a more high end table. I'm sure you know that I recommend Teres as the best TT for the least money. I have a Teres 245 with OL Silver, and it is a sweetheart! I'd seriously recommend looking in that direction.

Chazzbo, not really sure what you mean by downsizing "size wise". But the Rega and OL arms are not nearly as easy to do a VTA adjustment on, as the VPI arms. But they can be adjusted, as long as you have the adjuster, that is normally included on the modded arms. Standard Rega arms don't come with a VTA adjuster, but you can buy one separately and put it right on.

The modded Rega arms and OL arms perform very well, and can be surprising to those who have not heard them. Particularly the OL Silver, which would give any arm a run for the money. Even arms costing far more.

They are all very good value, for not alot of cash. Over-achiever, would be a good term for them.

Bill, the OL Silver has virtually identical dimensions to the Rega arms, so I am sure it will fit right in. I have never actually tried it, but I can't see that it would be any different, as far as fitting under the dustcover. Also it will fit right into the Rega armhole, so it should be a totally "drop-in" swap. You might have to slightly enlarge the hole in the plinth with a half-round file, to accomodate the VTA adjusting collar.

I do have the Heavyweight on my OL Silver, and yes it is an improvement. A pretty good one. I was surprised, actually, at how much improvement I got, on an arm that was already very very good. I would definitely recommend getting the Heavyweight on the OL Silver arm. You must specify the OL end-stub model when ordering.