Using a Bang & Olufsen Type 1658 Beolink Passive Amplifier As a Stand Alone Amp

Hello. I recently came across a Bang & Olufsen Type 1658 Beolink Passive Amplifier, and was wondering how I could use it as a normal amplifier. I know it needs a special cord. Does any one know what cable would fit? I do know I would have to externally control the volume level from the source.

Hi,

You can use it as regular amp.

You feed the audio line level signal via the powerlink socket.

Steve from sounds heavenly can provide you with a minijack > powerlink cable or RCA > powerlink cable.

But it needs a 'tricker' to turn on. So a modification is needed. You need to shorten pin 2 and 1 (if I remember correctly) to turn on the amp circuit. 

So a cable modification is needed. Steve can most likely help with that as well unless you can/will do some soldering yourselves.

Regards 

Ravsted

Hello. Thanks for the recommendation. I remember Steve talking about such cable, but couldn't find the video. I just checked your wiring for turning on the amp and it looks like it would work. I also make my own cables so I can make a push button on switch built into a cable. 

 

 

After looking quickly at my parts bin I found the socket and cable needed.

One last question, do I have to make a volume control for the amp? in other words will the amp be at 100% volume the whole time?

Hi 

First a note regarding the trigger for turning on the amp.

BeoLab speakers trigger via +2.5-5v on pin 4 (pin 2/7 is ground) 

After refreshing my memory the passive is different. Pretty sure it triggers on pin 1 instead of 4.

But I am pretty sure that I read somewhere that shortening 2 pins is sufficient. But can't find that currently. Will search and get back to you.

The amp will run 100%.

You'll have to regulate the input signal.

 

Noah:

Hello. I recently came across a Bang & Olufsen Type 1658 Beolink Passive Amplifier, and was wondering how I could use it as a normal amplifier. I know it needs a special cord. Does any one know what cable would fit? I do know I would have to externally control the volume level from the source.

Do you want to use it with B&o? And does this B&o has a PL connection? Then you can use a fully wired PL cable.

 

 

Found it 

https://archivedforum2.beoworld.org/forums/t/45686.aspx 

Shortening pin 1 and 2 should do the trick 

I update my first reply accordingly 

 

Cool, thanks for the help. 

I got my question answered, but I want to plug in a iPhone and power some speakers I have. 

I'm lookin for this since a long time so thank you.

Unfortunately it don't work on both Beolink Passive Type1656 and ML/MCL Converter Type 1651. :-(

Agreed, @matador43.  I measured a PowerLink cable at +12VDC for PWR (pin 1) and +7.5VDC for ~MUTE (pin 4) (i.e. positive voltage for *not* muted, goes to zero to mute).  Shorting pins 1&2 just grounds the PWR line, which I think turns the amp *off*, the opposite of what is desired?  

But @RaMaBo is often right and I am often wrong, so it would be nice if someone else could test... Maybe it matters if the 12V vs. 0V is externally supplied on pin 1 by the audio source on the PowerLink cable, vs. being disconnected floating and some kind of "sense" voltage is applied to pin 1 by the MCL Passive amp itself?  

I hope someone else can try this to verify it works, or explain how/why?

Correct - shorting pin 1 and 2 on BL passive doesn`t make sense at all. Bl passive needs 5V on pin 1 to power on - "newer" Beomastesr send on/off signal on pin 4 - so shorting pin 4 and 1 makes sense, or `redirect` pin 4 to pin 1 (BM - BL passive).

For Volume control and sound setting you need an IR receiver and a Beoremote.

BTW: the question from Carolpa has not been answered, what might be important.

Hope this helps

Stefan

Hi,

I will try to summarize:

- When BL Passive and ML/MCL Converter is used with a B&O master it must be connected with a fully wired PowerLink cable (i.e. MK2). It does not work with a MK3 cable. In a MK3 cable only PIN 2,3,4,5,7 is present. PIN 1 is not.

- If you use the PowerLink socket only (Not masterlink and IR) you don't need a Beoremote for volume control.

- Sounds Heavenly has a cable which includes a power supply (trigger) which will do the job. Designed exactly for this purpose.

- Noah wants to use his Beolink Passive with an iPhone.

- Below is the "standard" from the BeoTech site for Powerlink MK1 and MK2.

- RaMoBo claims that shortening PIN1 and PIN2 will turn on the "amp"

- In a dutch forum I read that supplying 5V to PIN1 with PIN2 as ground will turn on the Beolink Passive. No supply to PIN4

 

Looking forward to hear what Noah has learned in the meanwhile.......

 

Hello all. Im glad too see that this post is getting a lot of interaction.

As for testing this and such, I do not have the amplifier with me at the moment as I'm on vacation. I'm going to try shorting pins 1 and 2 first and seeing if I can figure it out myself. If I cannot, I will contact Steve at sounds heavenly and get a pre-made cable. From what I have read, shorting find 1 and 2 is on/off, then pins 3/5 are audio. 

When I get back home, I will try it out and report back. 

Thank you all for chipping in to this discussion. 

Ravsted:

- In a dutch forum I read that supplying 5V to PIN1 with PIN2 as ground will turn on the Beolink Passive. No supply to PIN4

Tried that too, Didn't work.

Also, it would be useful to always specify how is the wiring displayed: from plug side or solder side.
Nevertheless, do someone know the difference between pin 1 "PL ON" and pin 4 "PL SPEAKER ON"?

What I understand from Ramabo's Post is that by shortening pin 1 and pin 4 you have all chances to turn on the speaker whatever B&O master it is connected to via Powerlink or maybe even if it's not a fully wired PowerLink cable.

But it's not a solution to start the amp as a standalone unit which is what I would want to do without an external power supply only there for that purpose.

Then a question: wouldn't it be possible to force the unit to start at some relay level or similar? I mean whatever voltage to whatever pin is needed, it must just close or open some circuit somewhere. Can't that circuit be shorted even if it need the unit to be dismantled?

 

Honestly this post has gone all over the place haha. Im just going to order a cable from Sounds Heavenly so it just works. 

Also I'm going to pick up a pair of S-45's on the 20th!! I'll let you know how it goes. 

matador43:

Nevertheless, do someone know the difference between pin 1 "PL ON" and pin 4 "PL SPEAKER ON"?

In the olden days, starting up the amp was a separate function from closing the mute relay.  (A brief delay between the two would prevent a pop/thud in the speaker, though I don't know if B&O equipment needed this.  Aside: pressing the mute button would cause the relay to open but the audio signal was still supplied over the cable, which was one way MCL could manage local speaker muting but alternate room still playing.)  In modern times, powered-speaker amps turn on & off automatically, so "speaker on" always implies "amp on".  (Also no delay is necessary for modern amps, but if it were, it would be handled entirely within the speaker.)  This is why a "modern" MK.3 PowerLink cable doesn't have pin 1 wired, but the older MK.2 did.

matador43:

Ravsted:

- In a dutch forum I read that supplying 5V to PIN1 with PIN2 as ground will turn on the Beolink Passive. No supply to PIN4

Tried that too, Didn't work.

No surprise, *if* my explanation is correct: Voltage on 1 turns it on, AND voltage on 4 un-mutes it.

For anyone someday I tried this:

First thing first, let's be clear about pin location: When you look at the unit (from the outside) with the masterlink socket at your right and the speakers sockets at your left, pin 1 is at 3 o'clock, pin 2 is at 6 o'clock,  pin 4 is at 4:30.

- Shorting 1 and 2 or 1 and 4 or even 4 and 2 does nothing.

- Applying some voltage (I used a phone charger rated 5V, measured 7,5V) to pin 4 does nothing.

- Applying the same voltage to pin 1 makes the unit click and the led turn green.

Now I need to make a wire that allows audio+power to check if I get sound out of the converter.
Following Trackbeo's post  I guess in the worst case I would need to short pin 1 and pin 4 before sending voltage.

I'll tell you as soon as I try.

Tips til BL Passiv 1656. One was once told that this works. Good luck.

This is really useful. Thank you so much!