The perils of modifying gear

[Arkless Electronics]

The problem I have with modifications is that some people don't know when to stop, or what the consequences are of the changes they are making. I have absolutely no problem if people want to mess around with interconnect, speaker and mains cables as this is a fairly harmless (mostly...) pastime but, as an engineer, I do get quite irritated by enthusiastic bodgers thinking they know better than the qualified design teams of large organisations delving into equipment and faffing around with it. I know of several manufacturers' repair departments that spend much more time than they would like, undoing modifications to their products to make them work again, and I've done it myself on more than one occasion.

As an example, internet "wisdom" has long prevailed that changing capacitors can cure all known ills but often it can do more harm than good - witness someone I know of who changed all the caps in his high end direct drive turntable "as a precaution" and completely stopped it working! A friend of mine who does a great deal of repairs now adds a minimum of £10 to his repair costs if the owner confesses to having already changed capacitors - I've even known him to take the new ones out and put the old ones back in, once he's proved there is absolutely nothing wrong with them!

As an aside, the latest episode that is annoying me is a chap on a different forum who is currently "modifying" a fine pair of Mordaunt Short bookshelf speakers by slapping unnecessary coatings all over the drivers, attacking the cabinets with a chainsaw and junking the crossovers. I used to work with the guys who designed this speaker and we used them on many occasions for reference duty at Mordaunt Short - they were actually something of a 'sleeper' in the range and incorporated much of the technology that was adopted into the new range that followed them, at a lower price. However, the stuff he's removing was there for a very good reason and I would put money on it that the damn things will both measure appallingly and sound hideous when he's finished, which makes me a bit sad. And why is he doing all this? Because some other "expert" on the forum is egging him on by telling him it's a good idea!

It can be a nightmare yes... I usually add a hefty premium to my bill if equipment has been messed with and have also refused to repair a few bits of kit that have been got at to an extreme extent. On one occasion I had a big Jap amp in which must have cost the guy £30 in postage to send to me... after a quick look inside I repacked it and phoned him to say he will have to arrange to have it collected as I ain't touching it! Most of the wiring had been messed about with and all by twisting the ends together and wrapping them in sellotape!

[RothwellAudio]

Most of the wiring had been messed about with and all by twisting the ends together and wrapping them in sellotape!

Yeah, but I bet it was audiophile sellotape

[Marco]

You're forgetting about the effects of the famous 'wuffle dust'

Marco.

[montesquieu]

I've had quite a few bits of kit modded over the years with fancy caps, foo wiring, 'special' NOS valves etc but nowadays I've become much more skeptical. Yes in principle we know that mass-manufactured kit is often value engineered with cheapest possible bits used where the manufacturer thought they could get away with it. In such cases it might seem obvious to use better wire or caps but it has to be done with extreme caution otherwise changes can have unintended consequences.

Where I would draw the line is making actual changes to circuits, cone mass, cap values etc - this is almost always bad news unless it's done by someone who really understands at a deep level what's going on. (I feel shame here in having a decade or so ago paid quite a lot of cash to have a pretty rare SJS Model Two preamp 'improved', only to have Simon undo the mods later for a future owner and find that an expensive bit of Kondo signal cable had been run underneath a mains transformer resulting in a small but definite hum in one channel. This was restored to original along with removal of a forest of expensive but unnecessary bypass caps. I guess I'm not the only one that has this sort of 'live and learn' story thinking back).

These days, on the whole, I prefer to upgrade (as in replace) kit when funds allow rather than 'improve it' - on the basis only of auditioning it first. A rather more reliable way of improving the overall system.

[Radford Revival]

A good general rule of thumb is that to successfully modify a piece of equipment you need two criteria. One is you have to be as smart or smarter (in terms of electronics thinking) than the original designer of the equipment. The second being you need to establish what parameter or aspect of the performance you want to improve. Otherwise you're just soldering in parts to feel good.

[Macca]

Yeah, but I bet it was audiophile sellotape

Yes, the well-known sellotape mod. It gives more of a sense of the musicians playing together. Or sticking together. Can't remember which now.

[Marco]

I've had quite a few bits of kit modded over the years with fancy caps, foo wiring, 'special' NOS valves etc but nowadays I've become much more skeptical. Yes in principle we know that mass-manufactured kit is often value engineered with cheapest possible bits used where the manufacturer thought they could get away with it. In such cases it might seem obvious to use better wire or caps but it has to be done with extreme caution otherwise changes can have unintended consequences.

Where I would draw the line is making actual changes to circuits, cone mass, cap values etc - this is almost always bad news unless it's done by someone who really understands at a deep level what's going on. (I feel shame here in having a decade or so ago paid quite a lot of cash to have a pretty rare SJS Model Two preamp 'improved', only to have Simon undo the mods later for a future owner and find that an expensive bit of Kondo signal cable had been run underneath a mains transformer resulting in a small but definite hum in one channel. This was restored to original along with removal of a forest of expensive but unnecessary bypass caps. I guess I'm not the only one that has this sort of 'live and learn' story thinking back).

These days, on the whole, I prefer to upgrade (as in replace) kit when funds allow rather than 'improve it' - on the basis only of auditioning it first. A rather more reliable way of improving the overall system.

Good advice, Tom. I completely occur. When modifying anything, you have to have a goal in mind of what you want, and a coherent plan of action on how to achieve it, otherwise there's a very good chance of failure, and ending up worse off than you were when you started.

Marco.

[Marco]

Hi Will,

A good general rule of thumb is that to successfully modify a piece of equipment you need two criteria. One is you have to be as smart or smarter (in terms of electronics thinking) than the original designer of the equipment. The second being you need to establish what parameter or aspect of the performance you want to improve. Otherwise you're just soldering in parts to feel good.

Lol - I like that, and so true! I wouldn't dream of modifying anything at a fundamental level, such as you've outlined, as I simply don't have the necessary technical knowledge or skill set to do so - but I do have a very good pair of ears and a knack for discovering gear that has latent potential for exploiting!

Therefore, having successfully identified a particular piece of kit (usually high-quality vintage) I think has the potential to be even better after some judicious modifications, I ask one of my EE friends to do the work [I'm lucky that I know some very knowledgeable people], and follow their advice as to what they consider is the best way of going about things.

However, I'll be heavily involved in the selection of parts used, and unless given a good reason not to, whatever I fancy (and have paid for), which is electrically compatible, will be fitted. Quite often, with smaller projects, when it comes to component selection, it's simply a case of replacing like for like, in terms of electrical value

Therefore, fitting the same value caps, only of better quality, into the same place in the circuit, which is pretty safe to do, and on most commercial equipment will result in a notable sonic improvement. That's what I've done with my Croft preamp, for example, with great success (using Obbligato Teflon Tin-Foil coupling caps, Z-Foil resistors and Mundorf Tubecaps, at key points in the circuit).

Sonically, it now performs like a piece of equipment costing many, many times what I paid for it initially or have spent on it since, ultimately maximising 'SPPV', which for me is what it's all about - and many other areas of my system have been successfully modified in exactly the same way

Marco.

[Arkless Electronics]

Good advice, Tom. I completely occur. When modifying anything, you have to have a goal in mind of what you want, and a coherent plan of action on how to achieve it, otherwise there's a very good chance of failure, and ending up worse off than you were when you started.

Marco.

Unfortunately it isn't possible to do that.... One cannot decide, for example, to improve just/mainly the high treble... or the bass slam etc etc.

[Marco]

I don't set out with that type of goal, Jez. For me, it's about increasing realism and musicality [that's the aim], so that when I listen, instruments and voices sound as palpable and as convincing as possible.

If the by-product of that is improved bass or treble, then so be it

Marco.