Author Archives: mfspdesigns

How to make reliable A/B comparison tests between 2 headphone amps, 2 DAC, or 2 interconnect cables ?

Here is a small, simple and passive device, called “Passive Switch Box” (available in two forms: PSB2-1 and PSB2-1R), to simplify your audio comparison tests (A / B tests) between 2 audio components such as 2 headphone amplifiers, 2 DAC, 2 sources or even 2 interconnect cables.

Once correctly connected with your audio components, the PSB2-1 and PSB2-1R will enable easy switching of the 2 connected inputs using a single toggle switch.

PSB2-1 Switch between 2 headphone amplifiers

PSB2-1 Switch between 2 headphone amplifiers

The PSB2-1 and PSB2-1R are very simple to use, and due to their simple but yet high quality internal connections, they are completely transparent and doesn’t modify the input signals. The differences you may hear between “A” and “B” are due to the different devices you are comparing, so trust your ears, and decide for yourself if “A” is better than “B” !

In order to optimize the use for different A/B tests possibilities, the Passive Switch Box is available in 2 different forms with different inputs and output terminals (1/4″ jack or RCA): the PSB2-1 and the PSB2-1R. (click here for more information)

Here are 3 examples: (click on the desired link below)

  • How to make reliable A/B comparison tests between 2 interconnect RCA cables ? Use the PSB2-1R with the ICTester Box, or the PSB2-1 with adapters [RCA to 1/4″ jack] and the ICTester Box (available soon…)

Some wiring diagrams:

Passive Switch Box (PSB2-1) - Switch between 2 headphone amplifiers ( A/B test )

Passive Switch Box (PSB2-1) – Switch between 2 headphone amplifiers ( A/B test )

Passive Switch Box (PSB2-1R) - Switch between 2 DAC ( A/B test )

Passive Switch Box (PSB2-1R) – Switch between 2 DAC ( A/B test )

Passive Switch Box (PSB2-1) - Switch between 2 DAC ( A/B test ) using adapters

Passive Switch Box (PSB2-1) – Switch between 2 DAC ( A/B test ) using adapters

You can see all the products currently in stock and the special offers by visiting this page.

Don’t hesitate to contact me for any information. Worldwide shipping.

 

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How to make reliable A/B comparison tests between 2 headphone amplifiers?

Passive Switch Box PSB2-1 to switch between 2 headphone amplifiers (A/B comparison tests).

(the PSB2-1 can also be used to switch between 2 DAC via their RCA “line out” or other sources, just connect the PSB2-1 using the appropriate cables and/or adapters. more information here)

Passive Switch Box (PSB2-1) - Switch between 2 headphone amps

Passive Switch Box (PSB2-1) – Switch between 2 headphone amps for A/B tests

In order to make reliable A/B comparison tests between 2 headphone amplifiers, the PSB2-1 must be connected between your 2 headphone amplifiers and your headphone as shown in the diagram below. All connections are done using regular 1/4″ jacks.

  1. Connect the headphone output jacks of the 2 amplifiers respectively to the A and B jack INPUTS located on the back of the PSB2-1, using [stereo 1/4” jack plug – stereo 1/4” jack plug] cables (High quality Klotz cables, with Amphenol Nickel plated 1/4″ plugs can be provided optionally, or make your own cables)
  2. Connect your headphones to the 1/4” OUTPUT jack on the front of the PSB2-1.
  3. Use the toggle switch to switch between the A and B amplifiers signals. It is very important that you match the levels of the 2 headphone amplifiers carefully, in order to have a reliable comparison and A/B test.

The sonic differences (if they exist) between the connected headphone amplifiers will be easily apparent as we can switch from one to the other instantly using the toggle switch, without any other distraction (no need to stop listening and pull and plug cables…, just switch between A and B with the toggle switch…)

Only high quality components with internal silver plated contacts are used in the PSB2-1 (toggle switch and all 1/4” jack connectors).

PSB2-1 Switch between 2 headphone amplifiers

PSB2-1 Switch between 2 headphone amplifiers for A / B comparison tests

Passive Switch Box (PSB2-1) - Switch between 2 headphone amplifiers ( A/B test )

Passive Switch Box (PSB2-1) – Switch between 2 headphone amplifiers ( A/B test )

  • How to make reliable A/B comparison tests between 2 interconnect RCA cables? Use the PSB2-1R with the ICTester Box, or the PSB2-1 with adapters [RCA to 1/4″ jack] and the ICTester Box

You can see all the products currently in stock and the special offers by visiting this page.

Don’t hesitate to contact me for any information. Worldwide shipping.

How to make reliable A/B comparison tests between 2 DAC (line out RCA) ?

Passive Switch Box PSB2-1R to switch between 2 DAC (RCA “line out”) (A/B comparison tests).

(it is also possible to use the PSB2-1 to switch between 2 DAC via their RCA “line out” using the appropriate cables and/or adapters. more information and wiring diagram in the table here)

Passive Switch Box (PSB2-1R) - Switch between 2 DAC or 2 sources

Passive Switch Box (PSB2-1R) – Switch between 2 DAC or 2 sources RCA “line out”

In order to make A/B comparison tests between 2 DAC with the PSB2-1R (or PSB2-1 with adapters), it is necessary that the two DAC have a “line out” analog RCA output. The PSB2-1R must be connected between the 2 DAC and the amplifier as shown in the diagram below. All connections are done using [RCA – RCA] interconnect cables.

  1. Connect the DAC analog “LINE OUT” RCA (Left & Right) of each of the 2 DAC respectively to the A and B sets of RCA INPUTS located on the back of the PSB2-1R, using [RCA – RCA] interconnect cables. (High quality Klotz cables, with Neutrik gold plated connectors can be provided optionally)
  2. Connect the RCA OUTPUT on the front of the PSB2-1R to the analog “LINE IN” RCA set of the amplifier.
  3. Use the toggle switch to switch between the A and B DAC signals

The sonic differences (if they exist) between the connected DAC (or any other audio components connected via their “line out”) will be easily apparent as we can switch from one to the other instantly using the toggle switch, without any other distraction (no need to stop listening and pull and plug cables…, just switch between A and B with the toggle switch…)

Only high quality components with internal silver plated contacts are used in the PSB2-1R (4PDT toggle switch with silver plated contacts switching also the grounds, gold plated RCA connectors).

Passive Switch Box (PSB2-1R) - Switch between 2 DAC ( A/B test )

Passive Switch Box (PSB2-1R) – Switch between 2 DAC ( A/B test )

  • How to make reliable A/B comparison tests between 2 interconnect RCA cables? Use the PSB2-1R, or the PSB2-1 with adapters [RCA to 1/4″ jack]

You can see all the products currently in stock and the special offers by visiting this page.

Don’t hesitate to contact me for any information. Worldwide shipping.

How to make A/B comparison tests between 2 DAC (line out RCA) ? : PSB2-1 with adapters

The Passive Switch Box PSB2-1 was designed primarily to switch between 2 headphone amplifiers (A/B comparison tests), but with some adapters (and/or special cables) it can be used to switch between 2 DAC or 2 sources (RCA “line out”).

Note : For high quality switching and A/B comparison tests between 2 DAC or 2 sources (via their RCA “line out”), it is recommended to use the PSB2-1R which is equipped with 3 sets of RCA connectors, thus simplifying and reducing the connections of the DAC and amplifier, because no adapter is required. => How to make reliable A/B comparison tests between 2 DAC (line out RCA) – with the PSB2-1R

How to use adapters with the Passive Switch Box PSB2-1 to switch between 2 DAC (RCA “line out”) (A/B comparison tests).

Passive Switch Box (PSB2-1) - Switch between 2 headphone amps

Passive Switch Box (PSB2-1) – Switch between 2 DAC or sources RCA “line out”

In order to make A/B comparison tests between 2 DAC with the PSB2-1 , it is necessary that the two DAC have a “line out” analog RCA output. The PSB2-1 must be connected between the 2 DAC and the amplifier as shown in the diagram below. All connections require the proper interconnect cables and/or adapters.

  1. Connect three [1/4″ stereo jack plug – RCA stereo] adapters (or your own special cables) to the 1/4″ headphone jacks of the PSB2-1.
  2. Connect the DAC analog “LINE OUT” RCA (Left & Right) of each of the 2 DAC respectively to the A and B sets of the 2 adapters RCA INPUTS located on the back of the PSB2-1, using [RCA – RCA] interconnect cables. (High quality Klotz cables, with Neutrik gold plated connectors can be provided optionally)
  3. Connect the RCA OUTPUT of the adapter on the front of the PSB2-1 to the analog “LINE IN” RCA set of the amplifier.
  4. Use the toggle switch to switch between the A and B DAC signals

The sonic differences (if they exist) between the connected DAC (or any other audio components connected via their “line out”) will be easily apparent as we can switch from one to the other instantly using the toggle switch, without any other distraction (no need to stop listening and pull and plug cables…, just switch between A and B with the toggle switch…)

Only high quality components with internal silver plated contacts are used in the PSB2-1 (3PDT toggle switch with silver plated contacts, 1/4″ silver plated jacks).

Passive Switch Box (PSB2-1) - Switch between 2 DAC ( A/B test ) using adapters

 

  • How to make reliable A/B comparison tests between 2 interconnect RCA cables? Use the PSB2-1R, or the PSB2-1 with adapters [RCA to 1/4″ jack]

You can see all the products currently in stock and the special offers by visiting this page.

Don’t hesitate to contact me for any information. Worldwide shipping.

Headphone amps

I regularly have the following amplifiers (from AMB Labs kits) immediately available for shipping:
(aka MMM, M^3, Mcubed) : 3 ch. active ground MOSFET class A headphone amplifier , several options available (variable gain, bass boost, custom gain, other opamps…)
CK²III (Cavalli Kan Kumisa) : All discrete headphone amplifier

My builds are all housed in high quality custom handcrafted wood and aluminum enclosures.

If you need a different DIY amplifier (for example AMB Beta22, Bottlehead Crack, EHHA, O2 …), please visit my builds commissioning service page.

For prices and special offers, click here !

Here are some examples of my builds:

Cavalli Kan Kumisa (CK²III) headphone amplifier – mfspdesignsM³ (M^3, M3, MMM, Mcubed) headphone amplifier – mfspdesignsCavalli Kan Kumisa (CK²III) headphone amplifier – mfspdesignsM³ (M^3, M3, MMM, Mcubed) headphone amplifier – mfspdesignsM^3 Special Edition headphone amplifier with higher output bias and improved ventilation around output mosfet heatsinks - mfspdesignsM^3 Special Edition headphone amplifier with improved cooling - mfspdesigns

Some details:

You can see all the products currently in stock and the special offers by visiting this page.

Contact me for any information or pricing. Worldwide shipping.

Thanks for looking!

Copyright © 2014 mfspdesigns. All rights reserved.

Cavalli Kan Kumisa III Headphone Amplifier

The Cavalli Kan Kumisa III (CK²III or CKKIII) is a high quality desktop Headphone Amplifier. (more about it here)

Cavalli Kan Kumisa (CK²III) headphone amplifier - mfspdesignsCavalli Kan Kumisa (CKKIII) headphone amplifier - mfspdesigns

Cavalli Kan Kumisa (CKK III) headphone amplifier - mfspdesignsDSC02967-p3

My versions of the CK²III are enclosed in a high quality, compact and sturdy custom made enclosure made of wood (available in Mahogany or Walnut) and aluminum which houses the CK²III pcb and its power supply.

This amplifier provides a high voltage swing (20Vp-p) which is particularly suited to drive high impedance headphones.

Optionally available with DC offset protection and delay muting circuit (Epsilon12) to prevent any turn-on and turn-off noise and protect your headphones.

Optionally available with a white led illuminated volume knob and headphone jack aluminum (3.6mm) front plate.

Specifications:

Stereo Headphone Amplifier (all discrete)

Built in power supply.
Can be configured for 230 V or 115V
Toroidal transformer 30VAC, 25VA, 830mA

Option: Epsilon 12 – DC offset protection and delay muting circuit – (more about AMB Epsilon 12 here)

Enclosure: wood and aluminum with 3.6mm brushed aluminium front panel. (available in mahogany or walnut).
Massive (dia.28mm) aluminum knob for Volume.
Optionally available with a white led illuminated volume knob and headphone jack.
Stainless steel front power switch rated 3A, 250VAC.
Red led for power indicator.
Rubber feet.

ALPS RK27 “blue velvet” high quality potentiometer for Volume control
Std. gain: 9
Output bias set to 30mA
Neutrik 6,35mm jack
2 x Neutrik gold plated RCA for input

Output impedance: <0.5 Ohm
Max. Output voltage : 20Vp-p (7,07Vrms)
Power output: 1.4Wrms into 33 Ohms ; 0.15Wrms into 330 Ohms

dimensions (mm):
235x305x65 (incl. Knobs, RCA, feet)
235x280x55 (excl. Knobs, RCA, feet)

Weight: 2.1 kg

You can see all the products currently in stock and the special offers by visiting this page.

Don’t hesitate to contact me for any information. Worldwide shipping.

Thanks for looking!

Copyright © 2014 mfspdesigns. All rights reserved.

AMB M³ Headphone Amplifier

The M³, also called M3, M^3, M cubed, or MMM is a high-end Stereo Class A Headphone Amplifier with active ground designed by AMB Laboratories. (more about it here)

M³ high-end Stereo Class A Headphone Amplifier in high quality wood and aluminum enclosure - mfspdesignsM3 high-end Stereo Class A Headphones Amplifier - mfspdesignsM^3 high-end Stereo Class A Headphone Amplifier in high quality wood and aluminum enclosure - mfspdesignsM3 high-end Stereo Class A Headphone Amplifier in high quality wood and aluminum enclosure - mfspdesignsM^3 Special Edition headphone amplifier with improved cooling - mfspdesignsM^3 Special Edition headphone amplifier with higher output bias and improved ventilation around output mosfet heatsinks - mfspdesigns

For my versions of the M^3, I have created a high quality, compact and sturdy custom made enclosure made of wood (available in Mahogany or Walnut) and aluminum which houses the M³ and its Power Supply (Sigma 11 set at 24V).

Optionally available with DC offset protection and delay muting circuit (Epsilon12) to prevent any turn-on and turn-off noise and protect your headphones.

Also available in Special Edition enclosure with a large 42x232mm opening in the aluminum top plate for improved ventilation above the Mosfets output heatsinks in order to set up a higher output bias current up to 120mA without overheating issues.

This class A amplifier provides a high current MOSFET output stage which is particularly suited to drive low impedance headphones.

Specifications:

Stereo Class A Headphone Amplifier with active ground (3ch)

Sigma 11 – 24V power supply unit – (more about AMB Sigma 11 here)
Can be configured for 230 V or 115V
Toroidal transformer 24VAC, 1.04A, 25VA

Option: Epsilon 12 – DC offset protection and delay muting circuit – (more about AMB Epsilon 12 here)

Enclosure: wood and aluminum with 3.6mm brushed aluminium front panel. (available in mahogany or walnut).
Massive aluminum knobs for Volume and Gain.
Stainless steel front power switch rated 3A, 250VAC.
Blue led for power indicator.
Rubber feet.

ALPS RK27 “blue velvet” high quality potentiometers for Volume and Gain control
Variable gain 2 to 17 – (upon request, it can be made with a fixed gain)
Output bias set to 85mA in standard version.
AD8610 opamps in the 3 channels (you can easily change for other opamps)
Neutrik 6,35mm jack
2 x Neutrik gold plated RCA for input

Output impedance: <0.05 Ohm
Max. Output voltage : about 13Vp-p (4.6Vrms)
Power output: 0.6Wrms into 33 Ohms ; 2Wrms into 8 Ohms

dimensions (mm):
350x260x65 (incl. Knobs, RCA, feet)
350x235x55 (excl. Knobs, RCA, feet)

Weight: 2.6 kg

Headphone amplifier with matching headphone stand (Mahogany)

I use the M³ with my Sennheiser HD800 and a Marantz CD6004. The sound delivered by this amplifier is simply incredible: natural, very realistic, where every instrument is clearly separated, with a huge soundstage (on good recordings, you can pinpoint where each sound is coming from) and non-fatiguing for long listening sessions. If you enjoy headphone listening and if you are searching for an amplifier to drive your high-end headphones (in my opinion, it’s the perfect match for the HD800) and an affordable high quality headphone amp, the M3 is for you!!

You can see all the products currently in stock and the special offers by visiting this page.

Don’t hesitate to contact me for any information. Worldwide shipping.

Thanks for looking!

Copyright © 2014 mfspdesigns. All rights reserved.