jp200圖

红山老猫

哪 ！ 搭棚的老师就在楼上， 还不快拜 ！

F版， 开个玩笑， 轻松下， 收徒弟啦 ！

fung668

老猫咪开我玩笑啦~
对住老大我只是三脚猫功夫而已
话时话，下次来中国我带你去吃牛腩饭，超好食~！今天去虎门办点事，中午肚饿寻东西医肚，无意中被我找到一间不起眼的隐世的食店，包你吃过以后再也不吃斋了~

德宝

82# fung668


峰哥收徒弟啊!我都来了哇!叫声师傅先!请受徒弟一拜!

德宝

81# 红山老猫


猫版的靓机机出台了吗?靓机就要晒出来哇!指导下后辈们哇!

huihui03

极好，谢谢分享

lygzyx

没想到猫版与大家评价这么高，希望猫版能够出实作图。

wkdwkd

贴一个鬼子的DIY意见。他用的是330K的电路。
On DIY JP200

Norbert


Hi David,

I have successfully built a complete JP-200 "deluxe" kit (with some alterations, see below). Analogmetric as a company are easy to deal with but delivery is not exactly the fastest. They respond quick to emails.

If you are a beginner as a kit builder I have to warn you about lack of building support. The information on the analogmetric web site and forum is very basic and all you get. There is no overall wiring diagram or step by step instructions to lead you. So you have to know what goes where.

I have no idea if that preamp is even close to the original Jadis JP-200. I guess not because the original is a 4-chassis design including phono preamp stages.
The sound of this line stage is very much depending on the tubes you use. If you put in Mullards you get that typical (brown) Mullard sound which is not my cup of tea.

With the right tubes you can build a very transparent and detailled preamp featuring a huge soundstage. Before I have used a Silk-based TVC from DIYHifiSupply which tends more to the lean side. Compared to the TVC the JP-200 clone has more timbre, body and weight. Amount of detail is on the same (high) level.
Over the years I have come to the conclusion that a preamp is really a necessary component in a decent sounding system. Not to add voltage gain but to add those properties mentioned above. For me it is a deliberate departure from a "neutral" amplifier system. But sins of omission are not tolerated!

The rest of my system is a slightly moddified SlimDevices Transporter as source and Hypex-based Class-D poweramp feeding my Tannoy IIILZ Monitor Mk II speakers.

I have made the following alterations to the kit:

Power supply:

- Use the optionally available 10H choke
- Use 6x4 as rectifier tube (7-pin socket is not included!)
- Replace C1 and C3 with a single Mundorf tube cap of 10uF, 1000V
- Replace C7 with a TAD Oil Cap of 0,25uF, 600V

Amplifier board:

- Replace all resistors with Takman REY 0,5W metall film types
- Change R7A and B to 1kOhm
- Change R10A and B to 1,5 kOhm
- Change R14A and B to 100 Ohm
- Add C9A an B (which are not supplied with the kit) two TAD Oil Caps 0,25 uF / 600 V
- Replace C1A and B with Ampohm Aluminium Foil, Paper in Oil Cap 0,047 uF / 630 V
- Replace C2A and B with Ampohm Aluminium Foil, Paper in Oil Cap 0,1 uF / 630 V
- Replace C5A and B with Ampohm Aluminium Foil, Paper in Oil Cap 1,0 uF / 630 V (depending on the imput inpedance of your poweramp you might need a bigger value)
- Replace C4A and B with silver mica 8 pF / 500 V and place a silver mica 22 pF / 500 V capacitor between grid and cathode of T1A and B to fight self oscillation
- Use ECC81 / 12 AT7 for the cathode follower position (T3A and B) to lower output impedance

Lowering gain from 20 to 12dB:

- Change R5A and B to 33 kOhm
- Change R3A and B to 1 kOhm

General:

Be warned about the input selector and output delay protection kit which are included in the "deluxe" version of the kit: Both have ground planes which are connected to the local power supply ground. There is no dedicated signal ground plane! If you use the Analogmetric tube tube power supply there is only one low voltage supply you can use to feed both modules which is the unregulated part of the heater supply. Bad thing is that the heaters are connected to pin 4 and 5 of the ECC83s and pin 9 is grounded. As a result the ground plane of both modules is at -6,3V to ground! This converts ground planes to perfect anntenas.

- Add two ceramic 10 nF / 500 V capacitors to HF-wise shunt the "ground planes" of the input and output modules to signal ground
- The delivered Shuguang 12AX7B are not too bad for chinese tubes but I would recommend to find out which NOS tubes you like.

wkdwkd

Designator        Description        Quantity
C1A, C1B        WIMA 1uF/400V        2
C2A, C2B        WIMA 0.47uF/630V        2
C9A, C9B        　        　
C4A, C4B        1pF        2
C5A, C5B        WIMA 2uF/630V        2
C6A, C6B, C7A, C7B, C8A, C8B        Nichicon 100uF/450        6
R1A, R1B, R7A, R7B        Dale 1.68K        4
R2A, R2B        Dale 330K        2
R3A, R3B        Dale 27.4K        2
R4A, R4B        Dale 562R        2
R5A, R5B        Dale 330K        2
R6A, R6B, R9A, R9B, R13A, R13B        Dale 470K        6
R8A, R8B        Dale 10K        2
R10A, R10B, R14A, R14B        Dale 1K        4
R11A, R11B, R12A, R12B        Dale 100K        4
R15        Dale 10R        1
12AX7        　        6
Small 9 PIN socket        　        6
Blue 2 PIN socket        　        7
PCB        　        1

wkdwkd

JP-200电路图

红山老猫

如果从 听感上判断， 330K 屏阻版本， 肯定远远不如这个 165K屏阻的版本 ！

2113197

正好有个市面上流传的版本：----------果如猫版所言。

kenny

6X4能用吗？好似耐压低了点，EZ81倒是可以，小九脚。

kenny

貌似对12AX7来说，用330K的屏极电阻比165K的在共阴放大情况下失真要小一些。

leo_snow

假如没有阴极的75K电阻，这个电路应该也可以正常工作。反馈的100K电阻可以相当于阴极电阻的作用。希望有JP200的朋友或者有见过原机的朋友出来证实一下。
1238696
stjerry 发表于 2010-3-1 02:17

请教猫版有无试过这个75K阴极电阻真的可以没有吗？

红山老猫

95# leo_snow


leo 大哥好！

这只75K电阻， 会稍微提高输出阴藕的动作电流， 留着， 也没啥坏处啊 ！我自己就选择留着了 ！

leo_snow

猫兄客气了！感谢您的指点！这几日正在摆弄Cat SL-1前级，计划过些时日还要仿制M7和JP200，到时还要向您讨教，届时不要吝啬呀！

bg7jtg

电源部分的灯丝需要接地吗？