Anyone regret DRing a 500 ??

Posted by: Michael_B. on 29 March 2018

My 555 needs a new mech so I am planning to get all my 500 gear serviced and DRd while the CD player is being serviced.

I've only had one demo of a 500 vs 500 DR but it was a general Naim presentation in a hotel. I wasn't convinced the 500 conserved all the non-DR delicacy of touch and tone, but the demo was with speakers I'm not mad about and although the Naim guys present were confident it was fully run in, it could perhaps have done with more from reports here on the forum.

So here's my question: has anyone who has had their 500 DRd (or even 552, though I didn't have problems with what I heard there at the demo) feel that some its delicacy was sacrificed for grunt in their DR upgrade?

I've felt the need to post this in the light of a not dissimilar recent comment about the 250DR:

"I'd strongly second this. I tried a 250DR against my 250.2 and didn't like the result. Which was a bit strange, as I'd nonetheless agree that the DR is a better amplifier. But I didn't get on with its sound - it went deeper, which was nice, but it also introduced a grating quality in the upper mids. So I stayed with my 250.2. I posted a thread about it at the time and although we were in the minority, a few people found the same thing as me."

Cheers and of course many thanks in advance

Mike

Posted on: 03 April 2018 by tonym

Gavin L posted:
I am getting very close to my new 500DR arriving, and it will complete my active 500 setup (with DBLs). The other two 500 amps have yet to be DR’d, so the question I have to decide - what to DR (Hi/Med/Low)? At the moment, I am thinking the Med - which will add a lot as I would be switching out a 300. But is this the frequency that will suit DR the best?
In time, I am sure to have the others serviced/DR’d, but this will not be for some time...

The "Hi" one. Always put your best amp on the tweeter.

Posted on: 03 April 2018 by northpole

tonym posted:
Gavin L posted:
I am getting very close to my new 500DR arriving, and it will complete my active 500 setup (with DBLs). The other two 500 amps have yet to be DR’d, so the question I have to decide - what to DR (Hi/Med/Low)? At the moment, I am thinking the Med - which will add a lot as I would be switching out a 300. But is this the frequency that will suit DR the best?
In time, I am sure to have the others serviced/DR’d, but this will not be for some time...
The "Hi" one. Always put your best amp on the tweeter.

I have no experience with active but I am sure I recall a lengthy post on this subject a few years back where, if memory serves (unlikely!) the OP had to compromise with a 250 in the mix. The conclusion was very much in line with Tony's suggestion - the tweeter demands the best supply.

Peter

Posted on: 03 April 2018 by Gavin L

That original post may have been me as I started out with 250/250/300. Then 250/300/500. Now 500/300/500. I have always preferred the Bass over the Tweeter. But in any combination, you are always missing something.

On another post, DB was speculating that the Mid might benefit. This has some logic as it is not just about power to keep a tight grip on control. I will certainly try this combination and I am looking forward to getting more out of the vocals.

I was just wondering if the qualities DR brings might be better suited to mid/vocals than say other parts or the audio spectrum?

I guess I will find out soon enough, but the speaker cable lengths will work better (slightly) if I can put the amps in their final location.

Posted on: 03 April 2018 by sean

Gavin,

In the past it was always perceived wisdom to put your best amp on the treble as it has the biggest frequency span of them all. I guess in your case you will now be wondering which is your 'best' amp and which amp suits which frequency spectrum better? You will also not know for a while as the new DR'd amp will have to run in and then there is the fun (not) of swapping cables/amps over to see what you prefer. I am presuming that you are going to be heading towards 3 X 500's all DR'd and until then there will always be a certain degree of imbalance in your sound until this is achieved, either that or you decide the DR thing is not for you and you downgrade/go back to a non DR'd 500. Anyhoos, enjoy the ride and I hope you get to what your trying to achieve.

Sean.

Posted on: 03 April 2018 by Beachcomber

I know that this is the usual advice, but I am puzzled. IWHT that the bass drivers need the amps with the most power and greatest slew rate - at any rate a rather different set of needs from what the tweeter needs. ISTR years ago someone suggesting different amplifier designs for each drive for active systems.

So for the bass you need lots of current handling, but not so much with the tweeter, where you need fast voltage swings. Not so?

Cheers

Steve

Posted on: 03 April 2018 by tonym

Not so Steve. As has been pointed out, the tweeter has to handle the greater range of frequencies than the other drivers, and has to portray the subtlest of sounds. I did try a “Wonky” setup on my DBLs, using a 250.2 with my two 500s, but no matter what combination I tried, the system drew attention to the lesser amp., most obviously when the 250.2 was on the tweeter. Remember, Naim active speakers were designed to use the same amp on their drivers.

Posted on: 03 April 2018 by Dave***t

Is it not also the case that with many speakers, the trickiest load is presented at tweeter frequencies?

I've no expertise to back that up, I just got the impression from somewhere or other!

Posted on: 03 April 2018 by Beachcomber

tonym posted:
Not so Steve. As has been pointed out, the tweeter has to handle the greater range of frequencies than the other drivers, and has to portray the subtlest of sounds. I did try a “Wonky” setup on my DBLs, using a 250.2 with my two 500s, but no matter what combination I tried, the system drew attention to the lesser amp., most obviously when the 250.2 was on the tweeter. Remember, Naim active speakers were designed to use the same amp on their drivers.

I can see that the tweeter amp has to handle a greater range of frequencies, but it isn't pushing out as much amperage, is it? So in principle you could design an amp which does DC to 1000 Hz at huge amperages, and another amp which does 40K to 500 Hz (say) but not at such large amps. AIUI (and I only know the very basics of amplifier design) you could take different design decisions for each amp... But what your findings suggest is that the tweeters need the greater current. Which seems odd, because they are moving much lower masses both in terms of volume of air, and in terms of moving parts of the speaker.

Cheers

Steve

Posted on: 03 April 2018 by Gavin L

I can believe that you want to make sure that you have a powerful amp driving the tweeter. I don’t know the technical reasons, but there is a lot of movement at these high frequencies.

But with DR, it is not about absolute power. So I was wondering if the benefit of the lower noise floor would be more beneficial at a specific frequency range.