TWL's Hi Fi Mod & Doug's VTF tweak

Well, after having all of the necessary pieces to do these two mods for about 4 months, I finally got off my A$$ & did them tonight.

The Process:

Hi Fi Mod:

If you have not done it yet, do it! It took me 7 minutes from start to finish. That includes boring a concave surface in the weights, polishing the weights, searching through the hifi junk box to find Blue tack, and mounting them.

VTF Mod:

I actually had this one before, but took it off because it wouldn't stay stable with no holes to hold it. Now that I have the weights on, I made a new one. Took me 2.5 minutes to smooth, bend, and install the biggest paper clip I could find. Fits the weight holes perfectly now!


The immediate increase in bass tightness is amazing. All around the sound is more focused, tighter, and a little more dynamic. I've been listening to albums I know VERY WELL for the last 2 hours, ans I still can't believe that something that cost me $1.32 (I got extra weights) makes more difference than changing from the Soro SE pre, phono, and Microgroove to the Supratek. I kid you not, skeptics, try it.

Coupled with the VTF adjustability of Doug's mod, while the album is PLAYING, with my OL (Rega) arm, well, I just can't say enough. Now I can play with the VTF to a much finer degree. I'm so glad I didn't spend $200+ on a digital gauge. The Shure gets it close enough, and the paper clip dials it in.

What got me started installing these two mods tonight was the distilled water thread. I'll say it again: There are people here who have more patience and creativity than most of us, and I've learned that if they say it works, I can probably count on it working. They are willing to try "all kinds of mean, nasty, and ugly things" (thanks Arlo), and then let the rest of us know what works, and what DOES NOT.

I kid you not, for 2 bucks and about 10 minutes you will think you've got a new system. I cannot stress how much impact the two mods make. Sure, you can go spend a ton of money and get the same results, easily. But, I've got about $500 in my arm & cartridge, and I think I would have to spend 5-6 times that for a very incremental improvement. An Illustrious and a 901 cost about 6 times my investment. Is it worth it? Sure, and I'll do it one of these days, down the road. But I figure what the hell, I built the Teres, I can do this!

I believe even the most non-DIY capable people out there can do this for themselves. If you can't, email Tom. He'll be happy to send you a little kit to install the HiFi mod. After that, Doug's mod is so easy it's not funny.

And, if you can't get a hold of either one of them, email me, and I would be more than happy to help you get going. That ought to tell you what I think of these mods, if for some reason you missed it in this post!

Joe, could you post some closeup pictures please?
Sure can. I took two to give those of you who have not seen it to check it out.


Side view

I didn't reduce the quality & size of these pics like I did on most of the ones on my site. So, closeups you ask for, closeups you get!
Thanks, Joe! Glad you have found the time to make the HiFi mod and VTF tweak.

I guess now you see that I was not exaggerating.

It's been almost 2 years now, since I first posted the thread about this HiFi mod. Many people have done it, and all had the same impressions you did. Probably the most "bang for the buck" that you can get with a Rega or OL Silver tonearm.

Most of the users that have tried this have emailed me with flabbergasted and glowing comments about how much transformation is made to the sound.

I would caution, however, that this mod is tuned to perform with low compliance to medium compliance cartridges, and could cause lateral mass/resonance mismatch with Grado or other high compliance cartridges. It is a lateral mass increase, so it has an effect in that area, and is tuned for cartridges from 5cu - 15cu. Higher compliance cartridges have less/or no need for this mod, since their suspensions have less ability to move the standard mass of the arm laterally.

For those with any of the DL103 series, Shelter, Koetsu, Lyra, Benz, Dynavector, Clearaudio, Transfiguration, ZYX, etc, this mod is a big improvement for very low bucks.

Shelters especially, are very VTF sensitive, and dialing them in on-the-fly with Doug's VTF mod is very easy and provides excellent results. With the combo of both of these mods, it will sound like you have a new, very expensive tonearm. No exaggeration.
Can someone point me to the orginal threads on how to do these tweaks. Thanks.
twl's mod
Thanks for the great pictures, Joe!

Wondering aloud:
If someone was to use one of Chris Brady's new on-the-fly VTA adjusters would it be logical to think that one could make three or so of Doug's VTF wires for varying degrees of VTF adjustment? Perhaps they could be made like increasingly smaller loops so that the distance from the pivot to the contact point on the arm would be farther down the arm for each one. Seems like there is room to drill a hole above and below the center hole for two more pivot points. I'm not really sure if it is just the weight of the paper clip or the distance down the arm that makes it work.

Sorry, I don't have an arm/cartridge combo suited to try this on or I would happily "guinea pig" this myself.
It looks like Tom modified the HiFi mod. Mine is bigger than yours. I wonder if they sound the same? I was very impressed when I added Tom's mod to my Rega arm. It was worth every penny I spent on it.
I just used different weights. I like the shorter/fatter ones. They are 1/2 oz wieghts that I took a little off so I could get the concave to match the convex surfce of the bearing cap. This isn't one from Tom, I just winged it from his post.

And Nrchy, you are right. It was worth all of the 132 pennies I spent!
I bought the mod from Tom but have not yet installed it on my arm because the concave surface of the weights is not that good a match to the convex bearing surface caps. With superglue, you need a pretty good tight fit. Do I take it from Joe's post that he installed them with Blue tack rather than glue? I would prefer that since it would then be reversible.
Yep, Blue tack.

Nice!!! I have both mods in my OL Silver arm as well! What you described is right on the money.

I only have a picture of the TWL mod and you can see it in my system page. The weights, although not visible in the pic, has the initial "T.W.L." inscribed by the man himself.
Good job, Jphii/Joe!
I used blu-tack too & I feel that was the better way for me to go as I can undo the mod should I sell off the tonearm in the future.

BTW Joe, I'm in NC too - in the Piedmont Triad area, not too far from you. One day I'd like to come over & visit + see your self-made Teres TT.

Good job as usual and thanks for the pix. No need for me to say more, this is simply a mandatory, no-brainer upgrade for anyone with a Rega/OL arm and a low-mid compliance cartridge. In all our time living with both mods (we discovered the VTF mod while demoing the HIFI mod) there have been no downsides.

Note to all: the VTF mod should properly be called Paul's Mod. I stuck the HIFI mod weights on with a bent paper clip for testing, but my partner is the one who immediately recognized that swivelling the clip fore or aft would affect VTF in a controllable fashion.

Here's a link to the original thread for those who need more help than Joe's picture! ;-)

BTW Joe, nice round curve on the paper clip. Ours is sort of an upside-down "V" shape. Yours is better looking.

VTF change would be affected both by the weight of the paper clip and the distance forward or aft of the pivot.
There are two issues that one might want to address: the overall range of VTF's that can be achieved without moving the C/W and the fineness of adjustment within that range.

Adjustment range
On our rig the one clip gives a range of slightly more than .3g. Moving the clip away from vertical adds or subtracts up to .15g. That's enough range so that I only have to move the counterweight twice a year. In the Autumn I set the C/W so that VTF is 1.85G with the paper clip vertical. This gives me a useable range of 1.70-2.00g, ideal for a Shelter 901 during colder weather. In the Spring I back the C/W off so the center point is 1.70g, with a range of 1.55-1.85g. This is good for all Summer.

Adjustment fineness
With only .15g difference between straight vertical and nearly flat horizontal, it's easy to hit a spot withing .01g. If I really cared, I could drag out my digital scale and set it for exactly 1.77g, or whatever. This would be silly of course. I use the scale to set the counterweight to the appropriate point (as mentioned above) then fine tune the paper clip by listening to music. Who cares whether you're at exactly 1.77 or 1.81?

As Twl mentioned, the Shelter cartridges (501 and 901 anyway) are amazingly VTF sensitive, and the right setting is heavily dependent on the weather. We find ourselves fiddling the paper clip nearly every day, no doubt due to the very changeable weather here in New England. Nevertheless, for our purposes the range and the resolution afforded by a single paper clip are more than sufficient.

Folks, I just wrote nine paragraphs about a paper clip. Now there's an assignment any sadistic English teacher could hand out with pride.
"Folks, I just wrote nine paragraphs about a paper clip. Now there's an assignment any sadistic English teacher could hand out with pride."


Thanks for the chuckle and the explanation. Now I see how the one clip can give you some variable adjustment. I guess I always thought of the clip as either laying on the arm or standing straight up.

I know what you mean about this New England weather!