Advice on new Quad based system

Rob I think I'll start another thread on DACs then!

I wish I had the competence to do what goodguy can do. For me, the idea was to get a system working more or less as originally intended, one which would last a long time and not require any upgrading. Having searched for ages to get amps in excellent original condition, it wouldn't make sense to make major changes to them, even if I could afford to.

And now that SWMBO is asking how long that old turntable will be in plain sight, I need to save up for a shed!

 

If you are happy with your amp then that's great. However hearing a huge difference with such a change is unlikely in theory so if you really want to find out what your changes did you need proper listening controls. The amp should be compared side by side with an original spec version, while hiding the identity of which is playing.

 

I am afraid i will have to disagree with you, as i have actually done this mod and am not speaking from a theoretical point of view.

But hardworking has indicated he does not wish to take the matter any further.

It is interesting to note that you can mod a piece of equipment, spend days redesigning, and at the end of it all there is little difference compared to stock. On the other hand some equipment responds wonderfully to modifications and sounds so much better when compared to the original

 

Not just theory here either, as a pile of toroids will attest during a bout of prototyping last year. As Simon mentions above, you can produce small differences to the noise performance of the amplifier being driven but these are at low level, down around the amplifiers noise floor and often more to do with orientation of the toroid than the model.
If you examine a 306 with standard transformer it's actually a very quiet amplifier and its transformer VA rating is sufficient for its current rating.
I'm not for one moment suggesting anyone puts a cheap n nasty transformer in their amplifier, but that doesn't apply here as the 306 model is of good quality.

If a piece of equipment responds dramatically to a modification it's because of two possible reasons:

- The design was inadequate in the first place. Perhaps built down to a price, perhaps just plain poor, perhaps just old and relying on less than wonderful parts available at the time.

- You've fundamentally changed the design. As an example, if you have an amplifier with small output caps and you want to drive low impedance loads, making these substantially larger can produce a dramatic result - very measurable and audible.
Same goes for a phono stage which is rolling off at 40hz when you prevent this happening. Or a noisy op amp in a high gain, critical circuit position might well be improved by a modern low noise alternative, but the same op amp used elsewhere in a low or unity gain part of the circuit might bring no benefit whatsoever. So yes some things will respond to modification, some won't.

There is a third option, and that's that folk tend to hear what they expect. So having spent a great deal of time and effort fitting 'better' components there is always the tendency, without proper listening controls in place, to think you've made things better.
Done that myself many times and it always irks people to suggest that they might be mistaken for good reason - but it's human nature and we're all susceptible to some degree.

 

You say: "Not just theory here either"

But it is, as you have not done the actual quad mod itself so this is your uninformed, inexperienced point of view.


"The design was inadequate in the first place. Perhaps built down to a price, perhaps just plain poor, perhaps just old and relying on less than wonderful parts available at the time."

Again, this is a theory you cannot apply this to any and all pieces of equipment. This is extremely subjective.

"- You've fundamentally changed the design. As an example, if you have an amplifier with small output caps and you want to drive low impedance loads, making these substantially larger can produce a dramatic result - very measurable and audible."

I always replace with same size caps when upgrading. There are a lot of people on the net who have done capacitor upgrading and would strongly disagree with you.
You can keep the same size caps and notice big differences. Not all capacitors are created equal.

"There is a third option, and that's that folk tend to hear what they expect. So having spent a great deal of time and effort fitting 'better' components there is always the tendency, without proper listening controls in place, to think you've made things better."

Again this is a theory and extremely subjective and insulting to forum members, claiming we are so stupid and deaf we are living in some surreal world wherein our own senses are being called into question. Perhaps we have made things better, perhaps we are not as foolish as you think we are, did you ever consider that?

 

Hi goodguy,welcome to Audiosmile .
Just a quick question,are you sure you're on the right forum?
Are you a member or ex-member of any other forums?
This tends to be a bit different from some other places.Different opinions are always welcome here but somehow people manage to express them without being rude or disrespectful.Quite a change from some other places.
By the way I am not connected in any way with this forum, other than as a happy member.
Welcome again, Pete.

 

GoodGuy,

You should not feel insulted that your senses are called to question. I know it can feel that way as Rob said, but if you want to know the truth or post your findings as fact on an open forum you need to do this. I don't think anybody has a problem with your opinion, but if you want others to take it as truth you need some evidence. The old saying 'extraordinary claims require extraordinary evidence' comes to mind. Having 4-5 people come round your place and doing a level matched blind ABX would be great evidence!

Again I'd like to say, it is a pleasure that you want to share your experience. That is great and welcome, but please present it as such and accept opposite opinions too.

I design audio equipment and I question my senses all the time so please don't feel upset.

If you want to have a bit of fun, why not try my interactive amplifier test? https://www.audio-forums.com/as-rediect/showthread.php?t=30382