找回密碼
 註冊
樓主: alfcat

DIY Marantz 7C

[複製鏈接]
kkwan18 發表於 2007-12-19 21:08:54 | 顯示全部樓層
Hi Cat,

How much was the Marantz 7c kits cost u in total, I will be back in hong kong in Chinese new year so that i can pick 1 up....

Excuse my ignorance accphoto, where can i get the ladder type volume from as you mention (William)  

kkwan
accphoto 發表於 2007-12-19 23:38:05 | 顯示全部樓層
WIllian is the admin of HiFiFever......
kkwan18 發表於 2007-12-20 01:30:55 | 顯示全部樓層
Hey thanks accphoto for telling me......
 樓主| alfcat 發表於 2007-12-20 07:42:18 | 顯示全部樓層
Dear KKwan,

I got my Marantz 7C from www.my3c.net. The price there is in NT. Divide it by 4 and you get $ amount in Hong Kong. They ship worldwide. The KIT includes Transformer, Delay output unit and ALL parts like capacitors, resistors, vacuum tubes, etc.

My3c.net is associated with www.diyzone.net. From DIYZONE, they have passages teaching you (from different people) how to assemble the kits, very comprehensive.

There are lots of items for you to shop around from my3c.net. You can also find the Ladder Type Volume control there, either in KIT (DIY) or finished product.

In Hong Kong, you can find many shops selling these ladder type VR as well. They range from HK$ 4xx to over HK$ 2K.

I will bring your remote up to China now. If I am home early, will tell you about the news.

CAT
cyrus 發表於 2008-1-14 17:04:32 | 顯示全部樓層
Hi Alfcat,

Are the components you used (Holco/Dale resistors, WIMA/BHC capacitors, the transformer, etc) came with the package?  If not, where can you buy all those components?  Are they all matched with the circuit?  Is there any odd value resistor (e.g. 82K) that you can't find?  If true, can you share how you resolve this?

Best rgds,
 樓主| alfcat 發表於 2008-1-14 17:43:36 | 顯示全部樓層
Dear Cyrus,

Sure, I can share my experience with you.

Almost everything comes with the Package; Transformer, Delay output unit, tubes, capacitors, resisotrs ....

Items not included: On/Off switch, Case, Volume control, wiring (mine is pure silver). The RCA sockets and the Balance output socket comes with the case. The cover of the case (Entry100) has NO holes drilled! Be aware of this.

I did changed the CAPACITORS of the pre-amp. Very common ones and I used Auricaps. You can for sure find those in "Hoi Wan" down in 558 Nathan Road or so. Changing ALL the caps will cost you around HK$ 900.
I changed them because my colleague (who is the owner of this M7C now) would like to have more BASS.

You can order the whole thing from www.my3c.net. One word of reminder. Another active member said this set of Marantz 7C is not the best around as the voltage is a bit low. However, for just under HK$ 2000 with everything for a DIYer, it is worth as a beginner project.

Hope this helps.

CAT
cyrus 發表於 2008-1-15 00:30:38 | 顯示全部樓層
Thanks much, alfcat.
 樓主| alfcat 發表於 2008-1-16 13:07:31 | 顯示全部樓層
Dear Cyrus,

Any interests in constructing one? This set is very easy to do with good instructions downloadable from the net.

Hi Fi Fever also got this M7 kit. You have to give them some time to pack everything for you. The price is a bit higher but the quality is much better!

CAT
cyrus 發表於 2008-1-16 13:49:07 | 顯示全部樓層
Hi alfcat,

Really wanna get 1 but I want to attend a pre-amp training from Hifi Fever first, cos I know nothing about building an amplifier.  As you know, the PCB and Schematic won' tell you how to connect wires from/to transformer, RCA sockets, volume controls, selectors etc..., that's part of the amplifier.  After I gained the experience, I'll try to build 1 by myself.
accphoto 發表於 2008-1-16 13:54:29 | 顯示全部樓層
Cyrus,

Don't build this one, it sound so so, ask William to get you a real Marantz 7 kit from China, the pcb layout and it is using original value. or try Matisee reference.
 樓主| alfcat 發表於 2008-1-16 16:43:08 | 顯示全部樓層
Dear Cyrus,

What Accphoto said is true. This one is just a BUDGET model. Good only for a try out. If you want something that will last .... get the better one.

Remember, this one is just HK$ 2K or so. A much better one cost around double to triple the price. You have to pay to get a better one ... :

Joining Hi Fi Fever course is fun. If I can spare the time (& of course $$$), I would like to meet with them again.

CAT
accphoto 發表於 2008-1-16 21:58:06 | 顯示全部樓層
Actually, it should not cost that much. I had build a Marantz 7 ( the real circuit with 膽穩壓,using auricap and Elna Cereine ,it cost about 3K without the tube.
cyrus 發表於 2008-1-16 23:52:13 | 顯示全部樓層
That sounds good, can't wait to have my own one!!!
kkwan18 發表於 2008-1-17 07:27:03 | 顯示全部樓層
Hi Cat,

Thanks for the remote, its working fine now...

According to every body here its better to get a more expensive version of Marantz 7 then the 7c, or should i try the new LS7 Preamp kit {kit-ARCLS7} from hififever shop, it seem that the LS7 is a near identical copy of the original Audio research LS7, will it go with my Antique soundlab AQ1004 power amp to complete the system.

kkwan
accphoto 發表於 2008-1-17 08:32:21 | 顯示全部樓層
LS7 sound quite different to Marantz 7, it is a matter of taste. LS7 sound like modern tube amp which have more dynamic, extension and faster. It does not sound like a tube amp. The default kit using bennic capacitor which need to be changed. For the Marantz 7, if appropriate run-in and with better parts, it is more musical and sound "thicker". Your power amp i also important because sometimes it is a mix and match.
 樓主| alfcat 發表於 2008-1-17 09:11:33 | 顯示全部樓層
Dear Cyrus,

I mixed up Marantz 7's price with something else. The Marantz 7 should be around $ 3K without tubes and case, just like Accphoto said. And with that budget, the components are already very good ones.

CAT
cyrus 發表於 2008-1-17 11:15:02 | 顯示全部樓層
Thanks to Alfcat and Accphoto.  

I'm planning to join the pre-amp course, do you recommend any models other than Marantz 7?  They are now offering AudioNote M7, ARC LS-7, Conrad Johnson PV-3, Marantz 7, GG and 禾田茂氏.
accphoto 發表於 2008-1-17 21:39:04 | 顯示全部樓層
A lot of people like GG, but I need manage to get really good sound from this circuit. It is quite simple in effect and good for really beginner. From a design point of view, marantz 7 is the best because the cathod follower will result in lower output impedence. I had not tried audio note m7 and conard johnson , so I am unable to comment on it.
 樓主| alfcat 發表於 2008-1-18 08:38:25 | 顯示全部樓層
Dear Accphoto,

How do you feel about the McIntosh C22 from www.my3c.net? One of my colleagues is interested in this kit. He is thinking of buying it and wants me to assemble it for him.

I think it is better to check with you as you have more knowledge on this field.

BTW, I fixed the EL34 (one side). The sound is not impressive. As it was too late last night, no time for the second block. Will see if I can complete both tonight and have it assembled and go for a test.

CAT
accphoto 發表於 2008-1-18 12:07:09 | 顯示全部樓層
C22 is basically a Marantz 7 with different value. I think Marantz 7 will be better.

I have a Jadis JP-200 half finished, I do not know whether your friend will be interested, you can finished it off  for him. I am using premium parts like MIT and Philips Cap, just like the original one. .......Please PM me to discuss if your colleagues interested. I have PCB, tube stabilizer, transformer and case available at the moment.
 樓主| alfcat 發表於 2008-1-18 15:22:46 | 顯示全部樓層
Sent an email to your company's account

CAT
SSWONG 發表於 2008-1-30 13:53:20 | 顯示全部樓層
Accphoto,

Need your advice.

Recently i DIY a 5687 tube pre amp, when use on DVD player as a source, no hum/very little hum but when use Bada tube CDP as source will have high hum.

the hum sound is ngggg at woofer only. then i disconnect my grounding in my tube CDP, hum sound become worst, got eee sound from the tweeter as well (much more distortion).

i didn't ground my supply to the filament.

Besides, what shall i adjust if i replace the 12AX7 in M7 to 12AU7?

TQ
accphoto 發表於 2008-1-30 14:22:14 | 顯示全部樓層
Oh, it is a ground different between two devices. You need to check whether your tube CDP and your pre-amp had ground the 水線 to the case of the device or some even connect to the 水線. It is better to connect both  水線 to the case.
For filament supply, there is normally two ways in reducing the hum sound, some will ground one filament, other method  will connect a high voltage ( say 100V) to the filament and float the filament from the ground, both ways should be ok to reduce hum.

For change the 12AX7 to 12AU7, it is not that simple as these tube had different operating condition. Need to change the bias resistor and the 陰極 電阻。I will check my circuit with me tonight and let you know.
 樓主| alfcat 發表於 2008-1-31 22:01:37 | 顯示全部樓層
Dear Accphoto,

My colleague gave me a difficult question. He asked how is my Matisse stands up to your JP200? Which wins in what aspect?

Do you think you can make a comparison?

CAT
accphoto 發表於 2008-1-31 22:11:55 | 顯示全部樓層
no, i can really give you any comment as i have not finished the kit yet. But base on circuit design, Matisse is more dynamic and hifi and JP-200 should be more lay back and musical. It is really until you finish it and you do not really know how it sound. Does it sound chanllaging?
oldbeandad 發表於 2008-2-2 12:14:38 | 顯示全部樓層
Hi folks,

May I join in to bring your attention to a good pre-amp which is not as popular as the M7 and Matisse do.  It is called "Magus" of which the circuit was designed by Bruce Moore.  I have my Magus built 20 years ago and it is still with me now.  It has the phono stage, so I hook it up to my turntable.  For listening to CDs, I have the Matisse which was built almost 18 years ago if I am not mistaken.

There are 5 common tube pre-amp circuits introduced in the Audiophile (The high end audio journal of Hong Kong).  You guys may be interested in.

本帖子中包含更多資源

您需要 登錄 才可以下載或查看,沒有帳號?註冊

x
 樓主| alfcat 發表於 2008-2-3 09:24:28 | 顯示全部樓層
Dear Cheaplow,

Nice Sharing.

CAT
SSWONG 發表於 2008-2-4 11:15:02 | 顯示全部樓層
Dear Accphoto,

Since the preamp i make is in a wood box, so no grounding to the box. all grounding connecr to the main ground on the 3 pin plug.

for my CDP, the ground of the pcb is connected to a capcitor then to the chasis (to reduce rf) so the chassis is actually not grounded.
accphoto 發表於 2008-2-4 15:15:12 | 顯示全部樓層
Wooden box is always a problem for grounding. Did you got any metal plate on the wooden box, you can ground the earth to the metal plate to replace interface. Alternative, you can remove the cap on the cpd and ground it to see it will better or not.
 樓主| alfcat 發表於 2008-2-6 10:36:41 | 顯示全部樓層
之前我也想過用亞加力膠片做 case, 因為好有型. 但想到 Grounding 問題, 結果都係放棄 ....

CAT
SSWONG 發表於 2008-2-18 10:44:54 | 顯示全部樓層
Dear all,

My tube preamp is using 5687 tube (circuit close to audionote M7 but i run B+ at 130V only).
The noise reduce a lot after i do the following changes:

1) change to metal casing
2) restructure the grounding (use star grounding)
3) add in another C-R-C (total 4 CRC in series)
4) Reduce plate resistor ( increase the voltage supply)

Thank you everybody here for advice.
accphoto 發表於 2008-2-18 21:18:03 | 顯示全部樓層
130V is too low. I suggest you to increase the plate voltage to 200v and use the orignal value of resistor. You will find the ' 動態" is much better. For power supply, it is better to use CLC rather than CRC and you will find the noise is much lower when you use CLC. About 10 H coke will be better and cost very low ( about $ 100 if you buy local).
cyrus 發表於 2008-2-19 11:11:23 | 顯示全部樓層
Hi all C Hing,

Would like to know what is CRC and CLC.
accphoto 發表於 2008-2-19 11:50:29 | 顯示全部樓層
CRC = Capacitor + Resistor + Capacitor
CLC = Capactior + Coke + Capacitor

Ways to reduce ripples in power supply.
cyrus 發表於 2008-2-19 18:35:46 | 顯示全部樓層
Oh I see, thanks.
 樓主| alfcat 發表於 2008-2-19 19:58:45 | 顯示全部樓層
Dear Accphoto,

I think you mean "CHOKE", ha..ha... caught your mis-typing.

I agree with you, CLC should be better than CRC. But need to reserve room for the choke. It will be easier if DIY as we fix the dimensions ourselves. But if doing modification, depends on whether the case got room for a good choke, right?

CAT
accphoto 發表於 2008-2-20 01:14:46 | 顯示全部樓層
ka ka ka....... yes , I mean choke.... instead of coke......ka ka ka....
SSWONG 發表於 2008-2-21 17:13:10 | 顯示全部樓層
no source of cheap choke in malaysia at this moment..

i'm think instead of choke can i just use the inductor 10mH?

maybe use 1 C-RC follow by 1 CLC....
accphoto 發表於 2008-2-23 00:32:34 | 顯示全部樓層
One famous local manufacturer selling choke of 10H 100ma , for only $80 (about USd 10.00), Sound ok but of course not up to those japanese one like tango or tamura.

I know someone tried to use inductor but its effect is weak when compare to choke. I can help you to buy one or two .
SSWONG 發表於 2008-2-28 11:03:44 | 顯示全部樓層
Hi, Accphoto,

Can i have your email so that easier for me to contact you. Thne i can make arrangement with you to buy the choke....

thank you.
SSWONG 發表於 2008-3-6 14:26:48 | 顯示全部樓層
Hi,
attached is the 5687 tube pream/buffer i made.

Using the attached schematic but some changes
1) use only 4.7k plate resistor
2) B+ = 175v
3) chatode resistor =470R
4) SOLID STATE half wave rectifier
5) 1uF cap
6) C-R-C filter

next will make another 1 using
1) ~250v B+
2) 10K plate resitor
3) choke
4) 0.47uF mundorf ZN
5) separe box for power supply
hopefully sound will be much better

本帖子中包含更多資源

您需要 登錄 才可以下載或查看,沒有帳號?註冊

x
sjh327 發表於 2008-3-16 19:10:30 | 顯示全部樓層
M7的DIY文章又整理了9篇,大家可以參考下。

http://yunwt.u111.net/2wz2.html
SSWONG 發表於 2008-3-18 11:31:20 | 顯示全部樓層
云外天,

The tube preamp i made is same as your post 5687单管胆前级 in your web but i change the 1M to 470k.

plate resistor audionote using 50k, vt4 using 10k.

do u know what is the effect of th eplate resistor and the cathode resistor?
i understand that by using higher plate resistor can get better dynamic, how about cathode resistor and cathode capacitance? how's the value will affect the sound?


Do u think a DIY marantz M7 is much better than this 5687?
sjh327 發表於 2008-3-18 12:45:40 | 顯示全部樓層
謝謝你對我的信任,我英文不好,還是說用中文回復你吧,我用的是原廠的電路,屏極電阻是50K(兩個100K 2W電阻並聯),陰極電阻是470歐,輸出端是2微法(MKP)+0.1微法(油浸)+0.01微法(油浸)電容組合,聲音我還是很滿意的,聲音比較有活力和彈性,M7的優點是中頻,聽LP,FM,卡座估計會很合適的,但是高低頻略有欠缺。當然也可以通過調整耦合電容值的大小來進行補償。
SSWONG 發表於 2008-3-18 16:53:38 | 顯示全部樓層
No problem, i like to read mandarine/chinese. Sorry for inconvenient as i do not has software to key in chinese word.

By the way may i know your your voltage measurement on the position below during idle:

1) voltage before the 50K resistor
2) voltage after the 50k resistor (on the plate)
3) wht's teh value of capacitor (uf) at the chatode
4) voltage at chatode
abelwoo 發表於 2008-5-12 09:52:41 | 顯示全部樓層
[quote:90f23bdba0="WINDWSS"]no source of cheap choke in malaysia at this moment..

i'm think instead of choke can i just use the inductor 10mH?

maybe use 1 C-RC follow by 1 CLC....[/quote]

bro u try to find at FARNELL location at Subang Jaya.

http://my.farnell.com/inductors-chokes-coils
icefireman 發表於 2008-5-12 22:24:32 | 顯示全部樓層
To accphoto and alfcat,

You mentioned before that M7 cost around HK$3k (not include case and tube).  What components are included in it such as switch, colume control (which type), etc?   Is it used auricap and Elna?  Is it hard to solder all the things by myself?  Thank you.

Icefireman
 樓主| alfcat 發表於 2008-5-12 23:10:07 | 顯示全部樓層
Dear Icefireman,

The one I got from www.my3c.net is NOT the best around. I think HiFiFever got a much better version of the Marantz 7. The price may be a bit higher but it also depends on the caps and other stuffs you use.

I am now building another one based on the LITE Marantz 7 board. This time I use:

Two cases: small one for power supply, large one for M7
One LITE transformer
Rectification stage using Matisse design (transistors type), not tube
All Jensen caps on M7
Cardas RCA sockets
NO volume switch as I got one
ALL RMG resistors

The whole thing cost around HK$ 4,500 or less.

Where are you located? Hong Kong?

CAT
icefireman 發表於 2008-5-13 00:47:30 | 顯示全部樓層
Yea, I am living in Hong Kong.  I am just planning my next target.  Because I just finished my UCD180.  Need a pre-amp later.  So that's why I want to get more info.  Are you living in Hong Kong too, Alfcat?

Icefireman
 樓主| alfcat 發表於 2008-5-13 10:15:37 | 顯示全部樓層
Dear Icefireman,

Yes, I live in Hong Kong as well. I oredered the My3c.net M7 from their website. It is just an okay product; depends on how much you want to spend and your other components.

The following photos are the parts for my new M7.

CAT

本帖子中包含更多資源

您需要 登錄 才可以下載或查看,沒有帳號?註冊

x
您需要登錄後才可以回帖 登錄 | 註冊

本版積分規則

GMT+8, 2024-3-29 01:16 , Processed in 0.086168 second(s), 19 queries , Gzip On.

© 2001-2011 Powered by Discuz! X3.2. Theme By Yeei!

快速回復 返回頂部 返回列表