Dared MC-7P Upgrades

[Wire Nut]

Here is the post on AudioGon where I first saw some comments about the Dared.
Phil has some replies here:
AudiogoN Forums: Dared MC-7P optimal tubes
It talks about his bench testing it.

[Wire Nut]

Guys, I just wanted you to know that it is really tough going to cut through that foil to get rid of the grounding issue... use a very sharp, strong instrument to get it done.

I just purchased some EAR damping feet for the unit- I will install them and let you know if it helps the SQ.

[inline_phil]

Hi everyone,
Well the big question was: why did I do it? What made me tear apart a perfectly good sounding piece of gear in search for that audio grail?

The best way to explain it was that the sound was just "off" meaning that I could not put my finger on why I did not like prolonged listening to this unit. Having experience with ground loops in other gear, I decided to take the meter to the circuit board. And yes, I found what I typically did.

Pulling ground loops out is a simple thing to do once you really understand what they are and where they hide. WHY manufacturers build in ground loops into an otherwise excellent design, such as the Dared, is a mystery to me. The good news is that those with the right skills can transform a sow's ear into a silk purse.

I have updated the tube swap article to include the ground loop issue and one other I discovered while poking around: wrong values in the RIAA network. don;t get me started about stupid manufacturing mistakes but mine had one that is just inexcusable and points a finger at the quality control department.

So for those who want tips on "how to" without having to reinvent the wheel, contact me and I'll send you a copy of the whole series of tweaks, tube swaps, capacitor upgrades, RIAA fix, and ground loop fixes.
Cheers,

Philip Rastocny
philip@okstatealumni.org

[Wire Nut]

I asked Phil about the ground loops and I am going to try to find this one this weekend and put in the Rusky .01 Teflon bypass caps. I will post pix:

"Next is the one on the big power transformer. I measured on mine that the ground wire connected to the PC board is redundant. Measuring from ground to the PC board before and after lifting this wire read continuous as the the measurement from the transformer wire to ground. I believe that was the last one"

[inline_phil]

Please remember to take pictures and I'll fold them into the article.

[Wire Nut]

I have dozens of tubes of the ax, au variety and rolled a bunch into the 7P. I had the best luck with Brimar in the preamp section. I tried Mullard, EI, Telefunken, MiniWatt, RCA, Sylvania, and Amperex- the best in my system were the Brimar. Accurate with deep bass to sparkling highs!

[Wire Nut]

OMG-
You guys need to bypass your caps, I have not heard bass like this before, clarity like this before or just crystal clear highs. You can see the 4 Russian Teflons and the 2 Vishay- this is exceptional!

[Wire Nut]

Originally Posted by Wire Nut

OMG-
You guys need to bypass your caps, I have not heard bass like this before, clarity like this before or just crystal clear highs. You can see the 4 Russian Teflons and the 2 Vishay- this is exceptional!

I really should say that I have not heard anything in my system that sounds so good; some of my friends have better sounding preamps- however they spent four or five times more on them.

[stigs]

Your install looks great and I bet it sounds even better.

[MauroPerry]

Originally Posted by Wire Nut

I just got the Dared MC-7P preamp; I am pleased with the sound... but not impressed. I see lots of room for upgrading here so I thought I would start a post to see what others have done with this nice little preamp.
First it responds really well to tube rolling- it is very responsive to NOS tubes.
Feel free to post your results with different tubes.

Second I popped the top and there are these huge yellow block shaped caps in it (1.0 value). I think they have to go! Has anyone had experience cap rolling with this preamp?

I am purchasing some Russian FT3's to try in my power amp, so I think I will get an extra set to try in the only place that I see room for this large cap in this cramped preamp.

I am looking forward to some interchange here so we can all make out preamps better!

Here are a few photos of the belly of the beast.

Hello guys, are you sure that all signal capacitors are changed? Aren't the two small blue capacitors (0,47µ) connected directly (via 100 Ohm resistor) to the output? And aren't the green ones in the middle connected between the anode of 12AX7 and the grid of 12AT7?

Greetings
Perry