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Valve and Solid State Amplifier / Loudspeaker Stereo Switch Box - SW2/2.

SW2/2 Switch Box

I was recently commissioned to make a simple Stereo Amplifier/Loudspeaker switch box.
The difference to the multitude of A/B switch boxes available today is that this new switcher must allow Valve Amplifiers and/or Transistor Amps to be used transparently.

As you will know, if you leave a Valve Amplifier without a set of loudspeakers connected then the output stage will destroy itself causing an extensive repair bill.

Wish List:
2 x stereo Amplifiers - Valve and/or Solid State transparent
2 x sets of stereo loudspeakers
Common Earth for all negative amplifier and loudspeaker connections
Each Amplifier can drive speakers 1 or speakers 2
Each Amplifier can drive speakers 1 and speakers 2 without changing the impedance load to the amplifier
Each Amplifier has 2 x 4 Ohm dummy loads connected if it is switched out of circuit
There must be no switching noises through the loudspeakers
The switch box must be musically transparent.
The Switch Box should be capable of switching up to 10 Amps (1KW) per channel.
It should be IMPOSSIBLE to switch 2 x Amplifiers back to back!

Designing such a simple yet complex circuit has been a challenge. Free standing push button switches and toggle switches cannot safely take the power!
Relay drive is the best solution - so that the controlling switches can be miniature toggles. A power supply to drive the relays is required but, should this fail - then the amplifiers must see the dummy loads by default.

Housed in a lovely Chinese Black Anodised Case width 226mm (9 inches) Height 70mm (2.75 inches) Depth 271mm (10.75 inches).

Switch Control front panel and rear panels plug into the main Relay Board
The Boards

The construction.
The Boards

Dummy loads (4 Ohm per channel) and decoupling 2200uF Capacitors ensure constant impedance loading to the Amplifiers when speakers are 'paralleled'.
The Component Parts

The front panels are available in the Anodised Black ("Darth Vader") version or the original alloy silver

Toggle Switch Positions:

Switch 1 Controls Amplifier A:
UP = not connected to the loudspeakers - Dummy load connections enabled (blue warning light)
DOWN = Connected to at least one pair of loudspeakers dependent to Switch 2

Switch 2 Controls Amplifier A and Amplifier B connections:
UP = AMP A connected to SPKR 1, AMP B connected to SPKR 2
DOWN = AMP A connected to SPKR 2, AMP B connected to SPKR 1

Centre push switch = Power on with warning Red LED

Switch 3 Controls Loudspeaker connections:
UP = Loudspeaker Sets 1 or 2 dependent to the ACTIVE Amplifier
DOWN = Loudspeaker Sets 1 and 2 connected to the ACTIVE Amplifier
Loudspeaker 2nd set is connected via the 2200uF decoupling capacitors acting as a bass crossover shunt to frequencies below 20Hz.
By this crossover technology, the Active Amplifier will only see the impedance of the primary set of speakers even though all loudspeakers will be active.

Switch 4 Controls Amplifier B:
UP = not connected to the loudspeakers - Dummy load connections enabled (blue warning light)
DOWN = Connected to at least one pair of loudspeakers dependent to Switch 2

Rear Connections.
The Rear

Bi-Wire Versions are available to order.

Bi Wire means that each louspeaker is connected to independant amplifiers - one controlling the bass unit and one controlling the Mid/tops units.
So in all - 4 stereo amps to 2 stereo sets of speakers each module wired independantly.

The photo's below show a special build of 2 sets of Bi-Wire Amps into one set of master loudspeakers (bi-Wired). Hence - only one switch needed to say Amp Set 1 or Amp Set 2. Wider case shown (same width as a CD Player).

Contact Paul to discuss your Bi-Wire requirements.

Bi-Wire Bi-Wire Bi-Wire Bi-Wire
Warranty:

The ReelAudio Custom Built Baldwin SW2/2 Switch Boxes are guaranteed for a period of 12 months from the date of purchase.
Normal Usage is implied by the word 'Guarantee' and 'Warranty'.

Click Here to view the Products & Pricing Page.

All Warranty repairs are undertaken on a return to base principle.
Any carriage costs are the responsibility of the Client

REELAUDIO MAKES NO WARRANTY, EITHER EXPRESS OR IMPLIED WITH RESPECT TO ANY PRODUCT, AND SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, INCLUDING, WITHOUT LIMITATION, WARRANTIES FOR MERCHANTABILITY, NON-INFRINGEMENT AND FITNESS FOR ANY PARTICULAR PURPOSE. REELAUDIOS' SOLE OBLIGATION AND LIABILITY FOR PRODUCT DEFECTS SHALL BE, AT REELAUDIOS' OPTION, TO REPLACE SUCH DEFECTIVE PRODUCT OR REFUND TO BUYER THE AMOUNT PAID BY BUYER THEREFOR. IN NO EVENT SHALL REELAUDIOS' LIABILITY EXCEED THE BUYER'S PURCHASE PRICE. THE FOREGOING REMEDY SHALL BE SUBJECT TO BUYER'S WRITTEN NOTIFICATION OF DEFECT AND RETURN OF THE DEFECTIVE PRODUCT WITHIN NINETY (90) DAYS OF PURCHASE. THE FOREGOING REMEDY DOES NOT APPLY TO PRODUCTS THAT HAVE BEEN SUBJECTED TO MISUSE (INCLUDING WITHOUT LIMITATION STATIC DISCHARGE), NEGLECT, ACCIDENT OR MODIFICATION, OR TO PRODUCTS THAT HAVE BEEN SOLDERED OR ALTERED DURING ASSEMBLY, OR ARE OTHERWISE NOT CAPABLE OF BEING TESTED, OR IF DAMAGE OCCURS AS A RESULT OF THE FAILURE OF BUYER TO FOLLOW SPECIFIC INSTRUCTIONS.

IN NO EVENT SHALL REELAUDIO BE LIABLE TO THE BUYER OR TO ANY THIRD PARTY FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS, LOST SAVINGS, OR LOSS OF BUSINESS OPPORTUNITY) ARISING OUT OF OR RELATING TO ANY PRODUCT OR SERVICE PROVIDED OR TO BE PROVIDED BY REELAUDIO OR THE USE OR INABILITY TO USE THE SAME, EVEN IF REELAUDIO HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Units are Designed and Hand Built by:
Paul Baldwin
www.ReelAudio.Co.UK
BaldwinHiFi.Co.UK
12 Tack Lee Road
Yapton
Arundel
West Sussex
BN18 0HB - UK - Great Britain
Direct EMAIL: neverfinished0@hotmail.com
Tel: 01243 553231 - Mobile: 07858 089421
Paul will be unavailable from 27th June 2017 (for 10 days) while installing wiring and equipment into a new HiFi Venue in Ibiza
Please note: Paul may be contacted by telephone during his preferred admin period of between 5pm and 8pm. Thankyou.

Payment for Goods: PAYPAL Account: neverfinished0@hotmail.com
Please specify what you are buying within the PAYPAL Message Area when Making a Payment.

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