M7 Tube Preamp

M7 Tube Preamp

This is a true classic M7 tube preamp. This preamp has been revised several times to reach the current version. It is warm, natural and smooth, just like how a tube amp should sound.

Price: RM1290/unit

Features

• Tube: 6Z5P x1, 12ax7 x 3
• ALPS16 100K stereo volume attenuator
• Made in Taiwan 2x6 selector switch
• AC heating for 12ax7 for natural sound
• 0.8mm thickness stainless steel digitally pressed chassis
• Power transformer uses H360 0.5mm, 76x40 iron core, with double shielding for filament layers
• Tube rectification 6z5p for warm sound
• Point to point wiring for amplification stages, PCB for power supply
• Gold plated RCA, 4 sets of input, 1 set of output
• High grade good sounding capacitors are used: Wima MKP10, RIFA PHE426, IT, and etc
• Weight ~4-5KG
• Size: 32 x 17 x 5cm chassis, total height is 10cm with tubes/transformers
• Total height of 18cm needed for better ventilation
• Input: 110V-220Vac (240Vac), configurable
• Frequency response: 10 – 26kHz (+/-1dB)
• Gain: ~15
• THD: 0.08%
• SNR: 99dB

Customization & upgrades available. Please email for more details.

Audiobits

USB Power Supply Cleaner

USB Power Supply Cleaner

The USB Power Supply Cleaner (and strengthener too!) will clean up the USB supply noise and provide act as a power bank to supply back current when the devices connected to the USB ports or USB chain in the PC needs them. 


Why do we need to clean up the PC / Computer Audio System USB supply and strengthen it? For those in PC industry, they would have known. PC, desktop or notebook are commodities. The margin is so low that it every cents count! The whole system will be optimized in such a way that it will work and function correct at a certain margin, but not in a way that it is good for audio reproduction, with ultra clean environment and ultra low noise for highest SNR and lowest distortion, unlike the audio world, where everything is overkill and built for 200% - 1000% headroom. 

Therefore, unless you have a custom built PC just for computer audio system use, the motherboard will be designed the same. What we need, is to provide and external source of cleaning and additional clean supply to substantiate or support the audio application requirements. 

A USB Power Supply Cleaner will look like and ordinary power bank (below is just a sample but not the actual unit), with USB A or B output ports to connect to your PC. It, will have circuits to lower the supply noise, and provide auxiliary or supplementary power to the USB power rails. 

This USB power supply cleaner should be used together with USB ground cleaner for the best effect! 

Price:
- Level 0 (entry), RM300/unit
- Level 1 (intermediate), RM500/unit
- Level 2 (audiophile/advance) RM800/unit

Note: USB cable is NOT bundled. Audiophiles should get audiophile USB cables from certified USB cable manufacturers for best effects, the shorter the better!


http://audiobits-hifi.blogspot.my/2016/03/usb-ground-cleaner.html 

Audiobits

USB Ground Cleaner

USB Ground Cleaner

We have a converter cable for using the ground box with USB ports for PC or Computer Audio System. The converter cable will have Y-spade or banana plug at one end, and a USB A or USB B head on the other end to connect to a PC / Computer. 

Why do we need to clean up the PC / Computer Audio System ground? For those in PC industry, they would have known. A notebook or desktop PC is made up of tens and hundreds of individual power supplies on the motherboard to power tens and hundreds of IC (integrated circuits / chips / SoC / CPU). In order to make them small, light, efficient and cheap, they are mostly made up of switching regulators that generates noises everywhere in the PC. On top of that, the high speed signals from the communications between those circuits and chips generate noise too. All these will be riding on the ground of the USB port and being transmitted to your audio system. We definitely need to find ways to draw these noises away and using ground boxes or ground cleaner will be one of the effective means of doing so.
 The converter cable will be something similar to this below (copied from internet) but with better quality audiophile banana plugs or Y-spade and audiophile cabling. 

The USB Ground Cleaner using 3io Blackbox or Audiobits Ground Box will help you clean up the noise riding on the ground at the PC / computer audio system by drawing them all away, giving you darker background, cleaner highs, less harshness and clearer soundstage.

 For those that are unfamiliar with ground cleaner, please visit this link below:

http://audiobits-hifi.blogspot.my/2015/12/ground-box.html
http://jandkaudiodesign.blogspot.my/2015/03/3ios-blackbox-ground-box.html 

Audiobits

Kit Building Services

Clone kit building services

The M77 kit includes linestage (preamp) and a phono-stage. Customer purchased and asked us to build for a service fee. 

Notes
- Tubes and transformers are not included. Transformers are purchased from J&K Audio Design
- Dale and Philips milspec resistors are shown and depends on kit supplier. 
- Large capacitors and resistors might need supporting mechanical hardware.
- 2.4mm double sided gold plated PCB is used
- NOS TRW/Good-All coupling capacitors and gold plated ceramic tube sockets
- Can add chokes, stepped attenuator and various audiophile components as upgrades or features extension.

Required vacuum tubes for M7 (user purchase, not supplied, or we can help to source)
- 6X4 / EZ90 tube rectifier
- 12AY7 / 6072WA

Let us know if you want us to build amplifier kits. Email us at the form on the left!  

More pictures of chassis and M7 preamp that we help customers to build can be found here.

Again, we just provide build services for customers to build amplifiers of their choice.

 

Amplifier Kits

Kit building services - building high end preamp, integrated amplifier or power amplifier of your choices.

We have been approached several times and built kits of their choices, purchased from China or anywhere for several customers. They are interested at the kits sold in China but they have no means of DIY them due to technical capabilities. We came to the rescue, with the assistance to help them build the kits. 

Below is one a clone from China for about 1/20th of the price, for a very high end preamp - M7, priced over U$50,000

Let us know if you want us to build you other kits. Email us at the form on the left! 

We charge a fee for building, and measuring the kit before delivery. We do provide upgrade services too if they are not too happy with the clone kit stocked parts, with more high end parts like Duelund, Mundorf, Audionite UK electronics components. 

Note:
- We just provide building services. Customers can source the kits themselves, or seek our help to source the kits.
- Service charges are fixed. Do not negotiate, low ball or you will be ignored. 
- Vacuum tubes are either supplied from customers, or provided to us for measurement use.
- Power transformers are not part of the kit from China, and was sourced from J&K Audio Design. 
- Do not seek perfection on these kits. They are from China! We will try our best to perfect it but that's it.
- The stocked components may change anytime, depending on the vendor that distributes these kits.

Required vacuum tubes for M7
- 6X4 / EZ90 tube rectifier
- 12AY7 / 6072WA 

There are 2 types of M7 clone chassis available, a tall and a lower one.

Tall version: 

Low version

Let's take a look at the actual built PCB of a very high end preamp - M7.

 

 

 

M7 schematic is posted by a lot of people in the internet. You can easily Google for it yourselves. We do not want to post it here. 

Below are the one of the kits built with much better components after a significant amount of money is spent on buying the parts. The upgrade is all worth it. The improvement over the sound is substantial! 

Check it out:

We've helped customers to build clone M77. Email for more details.

Audiophile Headphone Amp

Audiophile Headphone Amp - A1

Summary

- All parts are original and authentic. Using authentic parts is not only safe but quality and longevity are ensured, to achieve the designedt target and performance. 

* Uses authentic original NE5534 Opamp, with Toshiba BD139 / BD140 matched transistors, in class A amplification.It can drive 32 Ohm headphones with ease.

- Price:  U$99 + shipping

Technical specifications

* Original and authentic Toshiba BD139 / BD140 transistors and NE5534 OPAMP.
* Input capacitor and interstage uses Siemens film 1UF capacitor for good clarity 
* Feedback capacitor uses Philips/BC, with 2x2200UF as main power supply bank
* 1% precision SMT resistor used on all the feedback and main circuit
* 1.6mm double sided PCG, 2.0 Oz copper for better power delivery
* Careful PCB layout, with single point ground for lowest noise operation

* Full ALU chassis, with copper RCA sockets 

* Chassis: 185mm W, 155mm D, 65mm H

* Input AC: 220V-240V

* Headphone impedance: 32 - 600 Ohm

* Frequency response: 20Hz - 20kHz

* Weight: 2KG net