RF 7 EvoTec " The queen is dead, long live the queen "

[MicroMara]

Two days ago I had to delete all my pictures because the 150 MB folder had exhausted its capacity. For this reason the summary of the RF7 MK II SE modification thread has been summarized on pages 12 and 13. All relevant pictures of the entire reconstruction as well as the modified external crossovers can only be found there. Thanx for your kind attention in this matter.

 

[Marco970]

Hallo to all, i'm new member of this community, i searched for the presentation section , but i didn't found it , so i suppose i can write directly here.

If not , i apologize  and if some of you guys show me where to write my presentation , i will be glad to start from there!

I'm an happy owner of this speakers , and i would be very grateful if Micromara could share the crossover schematic with values.

I searched for it in the topic , but i didn't found it , again probably i could have lost it , if it the case sorry!

I think they sound great as they are , but i'm really thinking to put my hands on them and try apply your mods , starting form the easy steps , to arrive at the end with the crossover .

Thanks again,

 

[MicroMara]

On 11/23/2020 at 1:54 PM, Marco970 said:

Hallo to all, i'm new member of this community, i searched for the presentation section , but i didn't found it , so i suppose i can write directly here.

If not , i apologize  and if some of you guys show me where to write my presentation , i will be glad to start from there!

I'm an happy owner of this speakers , and i would be very grateful if Micromara could share the crossover schematic with values.

I searched for it in the topic , but i didn't found it , again probably i could have lost it , if it the case sorry!

I think they sound great as they are , but i'm really thinking to put my hands on them and try apply your mods , starting form the easy steps , to arrive at the end with the crossover .

Thanks again,

 

 

Welcome to the Forum @Marco970. I am very happy that you have read this pages and that you are interested in this project.But you have set yourself some goals.

 

This is a project that took months to be realized. It cost nerves, energy and a lot of money. Nevertheless I would do it again and again, because the final result is in no relation to the effort. I also don't know if you can implement it the same way I did, without prior knowledge it gets complicated.

 

I also come from Germany, had parts made specially manufactured for me and don't know how you want to get the exact same parts, e.g. for example the new aluminium extensions for the cabinet decoupling  ,the AWG 16 Jantzen wax coils, the silver mica´s, the Mundorf MSupreme copper-Nickel or High End Thel resistors, and so on.  Some parts surely aren´t available on the american market.

 

I fully agree with you, the serial model of the RF7 MK II is and remains a great loudspeaker, otherwise I would not have bought it at that time. Moreover, before the RF7 MK II, I had speakers from the French company JM LAB FOCAL, the Electra 1038 II  ( 8.000 € ) which I then sold. The RF7 MK II had blown away the Focal ....

but the RF7 MK II SE is a phenomenon and easily blows a JM LAB STELLA UTOPIA III ( 16.000 € ) away.

 

The cross-over is the last step of a total of 8 modification phases. This was also by far the most difficult step in the implementation, because it is a modified cross-over, i.e. it was not mirrored 1:1 to the original.  You are welcome to get the X-over diagram from me, I will send it to you via the internal news portal. 

 

Furthermore I think you should get in contact with @Deangregarding the X-Over modification. He will surely be able to give you good tips or even rebuild the original X-over for you.

 

So far, so good ,I´ll remain with my best regards MicroMara

 

 

 

 

 

 

[MechEngVic]

Are you going to at least give him the schematics?

[MicroMara]

4 hours ago, MechEngVic said:

Are you going to at least give him the schematics?

I sent him via the personal messanger the same diagram you got from me a few months ago....Should be fine for the first thoughts into this project.

[MicroMara]

@Marco970    Here is an example of a crossover in the tweeter path from @Deangof a modified original RF7 MK II crossover, what he can do in the low pass he has to tell you himself.

 

 

 

[Marco970]

Thanks a lot George, and sorry for my late reply. 

Work is hard in these days and find some time for ourselves is never easy. 

Sincerely I don't know where to start my modification, most probably from the basic steps you also did. 

I know it takes time and the part that the most worry me is that, during some steps I will not be able to listen to my speakers!! 

I'm writing from Italy, we have  some good online seller for materials and components, but I'm not sure I can find everything and at which cost. 

It will be a long way to the top if you wanna rock 'n' roll, as ACDC said, but it is a way I would like to walk, step by step. 

Those speakers are really amazing as they are, I drive them with a tube amplifier that is smooth and warm and they perform great. 

I also have a SS amplifier and with it they really rocks! 

I don't know which is the best, they are different and both really good. 

Thanks all you. 

[MicroMara]

@Marco970

 

Let me check my personal files and I´ll send you a list from which manufactureres I odered those special parts and I´ll back you up with via the personal messanger. 

This may takes a couple of days. After each phase of the moddy, I let them play to listen to the changes for a couple of weeks before I contiuned with the next phase.

This also means that I had disassembled and reassembled the speakers countless times. I wanted to be sure that I wasn't just imagining all this, finally the measurements

I made at the end of the project have proven the sonic results. 

 

Regards

[MicroMara]

@Marco970  I have sent you a list with the first important materials for modification phase 1 & 2 .

 

Regards George

[MicroMara]

@Full Range   my moddy brother ...I´ve got a question ....

 

I know that you´re using the Jantzen cross caps mkp  in your low pass X-over section ,if I´m not wrong.  Do you know whether these black cross caps are better / different than the blue jantzen standard z caps ?  I got 2 x 15 pF blue standard z caps cobined with a superior z caps and wax coil in my external x-over. I used the cross caps in the low pass filter from my phono pre amp in combination with the red superior z caps and that moddy sounds amazing. Want to know whether a change in my X-Over would make sense or maybe senseless ? 

 

Your answer will be appreciated ....

 

 

 

[Full Range]

2 hours ago, MicroMara said:

my moddy brother ...I´ve got a question ....

 

I know that you´re using the Jantzen cross caps mkp  in your low pass X-over section ,if I´m not wrong.  Do you know whether these black cross caps are better / different than the blue jantzen standard z caps ?  I got 2 x 15 pF blue standard z caps cobined with a superior z caps and wax coil in my external x-over. I used the cross caps in the low pass filter from my phono pre amp in combination with the red superior z caps and that moddy sounds amazing. Want to know whether a change in my X-Over would make sense or maybe senseless ? 

 

Your answer will be appreciated ....

 

The black cross cap are good for Bass  — I would have preferred to use Superior Z but the available sizes were not available and or had to use many caps to make up the numbers 

 

However if you can get the correct size Superior Z they are preferred for Bass 

 

For mid range - Go the Red Superior Z cap

For Tweeter - Go the Alumen Z cap 

You will notice a huge difference in detail with my recommended choices 

 

[MicroMara]

This coming Friday I get a visit for 3 days- A good friend brings various audio devices to listen to them on my EvoTec. He knows the original RF7 MK II and wants to report in a German-speaking audio forum about the sonic difference to the RF 7 EvoTec. In addition, he will bring 2 Golden Note Class D 500 Watt amplifiers, two different tube preamps with phono stage, an Italian CDP with separate power supply, various DAC`s and of course a lot of music.  This will be an exciting weekend. I will take pictures and report next week.  

 

[MicroMara]

Well Guys ..it´s done ..the moddy from my Marantz SACDP/ DAC ...

 

That´s what we´ve done .....

 

*Drive and lens cleaned
*mechanical damping of the drive
*Mains phase connection revision
*Jensen double capacitors
*operating voltage blocking with additional film capacitors
*replacement of all old electrolytic capacitors against Elna Silmic / Panasonic
*Quartz amplification with Masterclock oscillator XO1.1
*Increase of power supply filtering
*Improvement of the converter filtering

 

My Model SA11 S-3

 

 

 inside pic seriell Marantz model sa11-s3

 

after ......Elna silmic caps all over ...

 

 

the new masterclock pcb with Elma Silmic /  Wima Caps

 

 

the new jensen filter elkos and some Elna Silmis

 

 

 

How  it sound´s ? 

The production model S 3 is already the further development of the SA 11 S1 / S2 / S3 series and should therefore be sonically mature. Is it also in relation to its predecessors . But now playing in an even higher league. More air between the voices and instruments on stage, an even deeper as well as finer resolution of the mid-highs in the stage, better basic dynamics in the fundamentals, the bass stagger even cleaner, sublime control and composure at high levels.    

 

I am even more surprised how the RF7 EvoTec acoustically implements the modifications made to the Marantz SA11-S3 so clearly audible.

 

So I would say .....a senseful audible investment ....

[MicroMara]

I use my thread to report on my HiFi workshop which I had conducted with a good friend for 3 days. He brought from his private collection various audio modules that we have tested on the RF7 EvoTec.

 

Day 1 

 

We used an italien Tube CDP CDP 7 ( on top ) with external Powersupply PSU 7 ( on the ground ) from the Company Lector Strumenti as well as a Lector Strumenti Tube Pre Amplifier " ZOE " ( ECC82 )  linked with my Cayin Mono Tubes . The price of those italiens are closed to 10 €K .

 

 

This combination sounded absolutely brilliant . Now I know that I need an additional Tube Pre Amplifier to be envolved into my Set Up. I don´t know if I can get a " Zoe " soon , maybe another one ..I will see.

 

 

 

[MicroMara]

Day 2

 

We used a NAD M 50 CDP with external DAC NAD M 51 in Combination with two Gold Note M 7 Class D Mono Amplifiers

 

 

Result ... Not worth to be mentioned ....we were not  excited ...the Lector / Cayin combination from day 1 was thousand times better.

 

Than we changed the class D Monos with a GoldNote PA1175 Stereo SS amplifiere

 

 

This set up was much better , but the NAD`s were still boring us . The SS power amp ist a fine piece of gear , but not better than the SS Stage of my Marantz SA11-S3 integrated . Than we connected my modified Marantz SA11-S3 SACD / DAC and we were happy again. My friend said the RF 7 EvoTec sounds like a speaker in the 20€K Range , he was more than impressed ...

[MicroMara]

Day 3 ...streaming day

 

We used a german XO Streamer ( 3K€ ) with some streaming and power interfaces on my Marantz SA11-S3 external Dac . The RF7 EvoTec was connected with the Gold Note SS Power Amp . We streamed files from Tidal .

 

 

 

Result : I´ve never listend to streaming files in such a brilliant resolution, almost perfect as DSD on my SACD . Now I want to buy a first class streamer as well . 

 

Than we disconnected the XO and used a Cambridge AZUR 851 D DAC with integrated SS Prestage on the Gold Note 1175 SS Power Amp

 

Result : The Cambridge Azur 851D is fine but hasn´t the quality of my Marantz PM11-S3 Pre Stage , it was a step backwards , but really not bad .

 

My goodness ...What a battle of materials   😂

 

Conclusion ......

The RF7 EvoTec is a loudspeaker that reveals every sound signature of different manufacturers, all strengths and weaknesses, ruthlessly. I am very glad to have done this workshop, because now I appreciate even more what I have for sensational speakers. I will now look at what new equipment will be integrated into my system.

 

 

 

 

 

[MicroMara]

Haven´t reported here for a while , many things have changed within the last 12 month with my own audio gear . 

 

I bought a new Tube Tube Preamp ..a Dynaco Pass 4 , completely modified by myself

 

 

 

He´s modified with Mundorf Silver Gold Caps, Mundorf EVO Alu/ Oil Caps bypassed with SilverMicas as well as power supply electrolytic capacitors fom Nichicon , Tube are from EH 6dj8 & 12AX7 all gold grid / pins,  of course he got new control knobs all over as well as new chrome feets

 

I sold my TT Micro Seiki DQX 500 and bought a Micro Seiki DQX 1000 with two arms , one is a modified and restored SME 3009 II Improved and the second is a MA 505 MK II modified and restored as well 

 

 

 

 

 

 

 

Have complete my collection of cartridges

These are the cartridges for the through modified SME 3009 tonearm , under all headshells ( all with new OFC headshell wiring ) there are teak spacers to optimize the precision of scanning

 

From right to left : ADC XLM MKII / Goldring G 900 SE / Goldring IGC 920 / Sonus GoldBlue . All needles are absolutely as new with less than 50 hours of operation.

 

Here are the cartridges for the modified MA 505 MK II tonearm on original Micro Seiki headshells with new OFC headshell wiring.

 

From right to left : Audio Technica AT20SLA / Grado Prestige Gold II / Osawa 301 / Nagaoka OS 300 MP , ditto here the operating hours

 

 

The ADC QLM 30 MK III

 

 

Grado Reference Platinium Wood

 

 

Stanton 681 EEE NoS and not used up to now

 

Super rare in the market

 

ADC XLM MKIV Nos and still in the box with the famouse " Pathemax Needle ( modified Shibata Grind )

 

 

The Audio Technica AT 7 V  and ADC XML MK III with Jico stylus are currently in use.  I'm just about to break in the new needles

 

 

[MicroMara]

Today I finished my new DIY Speaker Cable works , using now 16 x AWG 18 stranded copper wires and using the bi amp mode of my Marantz SS PM 11-S3  for the first time . The Dynaco tube Pre Pas4 as well as the Cayin tube mono amplifiers remain out of operation for the time being, because I still have to build the same cables for the monos to be connected to my DIY external X-Over´s

 

I use Beryllium Copper Banana Plugs from Germany

 

 

 

and german WBT Pure Copper Banana Plugs

 

 

Gonna report later again ...

[JohnJ]

The connections look great!

[MicroMara]

2 minutes ago, JohnJ said:

The connections look great!

low-mass and pure copper conductive paths