I have an offer for an early spec MP-3 with phono for around 1.300$. I am seriously considering purchasing it as I can't live anymore with Krell KAV 250p. The speakers are active (studio version) ATC 20A. They are great, extremely neutral, with amazing dynamic possibilites for such a small box (20liters) but can be very dry and lean if not correctly matched. They need a neutral, relaxed but slighly fuller partner. So the most common recommendation is either Ayre models or some better tube preamps.

The problem with MP-3 offerred to me is that it is an early model without any of the later upgrades that helped it gain such a good reputation. On the top I am based in Europe so the whole action with sending the preamp to the factory and back would set me a fortune and in that case I would definitely look for something else.

What I am wondering is if there are known resources on the net related to MP-3 tweaking, as precise as possible. Among local audiophiles here, there are several very good tube tweakers and technicians and I am pretty confident they would be able to implement anything that is not a rocket science. But it would be much easier to follow the known and proved steps.

I am also wondering what are the most essential upgrades that are by any means obligatory to perform immediatelly? I guess it must be power regulations, also hows about teflon caps, do they really work?

Also are there schematics for MP-3 available?

The next issue is tube lufe - as it has 11 of them, it makes it rather expensive to change them so i am wondering how often it is needed. In my home music playes 24/7. I can't remember when did I switched off my current system for the last time.

Last but not least, the common rave about MP-3 is its phono section. On contrary I seldomly use phono and I am wondering if its line sections is of similar quality (as you may hear different thoughts here)...

I know this is long, I apologize, but you can see that these are all pretty serious issues for someone who lives pretty far from the States, without much possibilities of using a good customer support.

Kind regards

Gordan

 Re: MP-3 DIY tweaking - possibility, resources? (long) - Legendre 06:42:17 05/02/06 (6)
 Re: MP-3 DIY tweaking - possibility, resources? (long) - gordan 07:05:21 05/02/06 (5)
 Re: MP-3 tube life - Ralph 08:30:44 05/02/06 (4)

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 Re: MP-3 DIY tweaking - possibility, resources? (long) - Legendre 06:42:17 05/02/06 (6)
 Re: MP-3 DIY tweaking - possibility, resources? (long) - gordan 07:05:21 05/02/06 (5)
 Re: MP-3 tube life - Ralph 08:30:44 05/02/06 (4)
 Re: MP-3 tube life - MP 06:34:13 02/11/17 (1)
 Re: MP-3 tube life - MP 06:47:36 02/11/17 (0)
 Re: MP-3 tube life - gordan 13:37:17 05/02/06 (1)
 Re: MP-3 tube life - Ralph 14:13:22 05/02/06 (0)

The only exception here is the addition of the HV regulators - this job is non-trivial, and requires a lot of cut & rework on the board. I've seen supposedly 'expert' individuals screw this job up.

If you can get back to me with the MP-3's serial number, or even better, a nice hi-res color photo of the internals, I can tell you the current state of the unit. $1300 is a very good price, and I'd think twice about letting it slip.

About the linestage / phono stage thing.. think of it this way: If the linestage didn't work very well, you'd probably never hear anything good about the phono, either.. difficult to have the latter without the former.

I will let you know the serial no as soon as I get it, the same goes for pics. I'll send you a private e-mail.

I am wondering about benefits of the regulators you mentioned. If this can't be done otherwise than by an Atma-sphere qualified person (and I can't send the preamp over to the States) does a lack of them really spoils the fun?

What is an average tube life?

The phono tubes do not last as long- as they fade they become noisy. 24/7 operation will kill them in about 5 months. But if you are not using the phono, I would remove the rear 4 12AT7s (you need some of them in place, even though you are not using them).

If you do decide to use the phono the good news is that the 12AT7 is inexpensive.

Since you have been used to a transistor preamp, you have also been used to running the preamp all the time. You don't need to do this with the MP-3 or MP-1. Especially if equipped with Teflon caps and the regulators, the MP-3 will 'warm up' in a surprisingly short time 30-45 minutes.

What are the usual prices for new tubes that do a good job in MP-3? Am I wrong that I read somewhere it doesn't like NOS tubes as they can't stand its heavy load?

There are all kinds of NOS tubes that can be used in the line section and the prices are all over the map! I prefer to use the stock tubes and spend the extra cash on more LPs...