Converting a stereo amp to a monoblock

It would seem easy to take the stereo channels of an amplifier and combine them for a single more powerful amplifier.

[@spacemissing]

The best answer to such a question is "If a particular stereo amplifier is capable of being bridged, its owner's manual will so state and will describe how to do it".

[@mikecoffee100]

Great Vids Hello From Vancouver BC Canada

[@michaelgu9907]

Watching from Philippines. Salite sir. I am here for the topic too😊

[@jch1967]

Hi Paul, Love your videos . I have done something like that using 2 stereo amp as MONO but biwire to the speaker in order to keep the crosstalk and PSU separate between channels , work great but still is not a MONO BLOCK So Channel R to the woofer and Channel L to the Mid and tweeter

[@mysock351C]

I tried this as a kid. It involved smoking wires and lots of sparks. Amplifier survived!

[@robertbenton2804]

There is somewhat of a solution. If your speakers have Bi Amp connections, which most do these days. Take Identical stereo amps and run the left channel to the tweeter, and the right channel to the woofer, do the same on the other side with the other stereo amplifier. I like to place each amp somewhere near each speaker, maybe on a small amp stand. On the two RCA inputs L and R use a Y adapter 2 to 1, so now one is only L and the other is only R. Although you really don't increase your wattage, each speaker gets its own private amp, each driver gets its own power, and both speakers get their own power section, cord, so that's a pretty neat trick. I hope this helps.

[@ulmontsmith8365]

Agree I was shouting the same thing at the screen, this is the best solution.

[@TheMeatloafSurprise]

Doesn't the woofer require significantly more power than the tweeter? By doing this, you're wasting the second channel powering solely the tweeter in order to give your woofer the few watts that were previously consumed by the tweeter.

[@sudd3660]

i got a related question, if you got two stereo power amps, and biamp a pair of 2 way speakers, the ones with dual binding posts. vertical bi-amping i think its called. do you gain any volume instead of using only one of those stereo amps or ability to provide more power at low ohm loads?

[@com456dj]

Nice Video

[@channelzero2252]

I recently found out about bridged amplifiers and found out that our amplifier can pur out a bridged signal and our speakers can accept a bridged signal. Would this give a better sound? It is a stereo amplifier (a Yamaha A-S701) and stereo speakers (the brand is Pure Acoustics but I forget which model).

[@marianneoelund2940]

Bridging isn't for *better* sound. It's for *more* sound. Before using bridged mode, make sure the amplifier is rated to drive half of your speaker's impedance.

[@anthonytan8751]

Does it help by replacing all stereo amps to mono block amps? Basically its like trading in back to the shop and purchase all mono amps to be installed. Thinking of running 7 mono amps to my vehicle which have abt 9 speakers 🤣. Other 2 speakers will be running 2 ch stereo amp instead. Not sure if i am correct for this staging structure?

[@sebastianpolcyn6358]

Nicely explained, but what we *really* need to know is the significance of the cardboard drawings in the background :)

[@dhpbear2]

Looks like a story board.

[@janinapalmer8368]

As a finalé to this bridge mode topic Paul should now go to the boardroom white board and show us just how you derive two equal anti phase signals from an unbalanced source ... Note :- there are several ways of driving bridge amplifiers by the way...

[@ChiefExecutiveOrbiter]

Great info...Didn't we get a PS video on this awhile back?

[@jordangogov5866]

The only way I think this may work with AMP not supporting "bridge" is for only subwoofer cuz they have options with dual coils, so you have 1 speakers fed like 2 speakers and this will work in the current arrangement of the AMP, I am thinking doing that with my 6 and 7 channel of the 7.2 receiver to power external passive subwoofer with dual coil, mt receiver has second zone so i can setup second zone to be the 6th and 7th unused channels to lets say CD input and connect the 2 sub outs to them and us all that power just for LPF twice cuz 2 channels to 1 speaker, and I can even turn up the volume of the subwoofer from my remote and this will make the subwoofer have the sound of my receiver like Paul says "use the hi level inputs of the active sub to get the same sound character as your amp" when I get that expensive dual coil speaker I will share will you

[@marianneoelund2940]

If your amplifier only has RCA inputs, and is not equipped with a bridge-mode feature, you can still set it up as a bridged (mono) amplifier by inserting a modified DI box or transformer isolator at one channel input to flip the phase. The usual cautions apply, e.g., make sure your amp can handle the lower impedance load that it will see. Of course, if you're a "true audiophile" you may turn your nose up at the thought of inserting a transformer into your signal path, in spite of the fact that's what "tube" amps do.

[@JazzyFizzleDrummers]

You could also do this with an opamp.

[@marianneoelund2940]

@@JazzyFizzleDrummers Op Amp plus a circuit board, connectors, case and power supply.

[@EElgar1857]

I believe a parallel connection IS the correct one for a tube amp, with output transformers. At least, that's what Music Reference says in my RM-9 Mk. 2 manual. But I don't do that; I have two RM-9s in a bi-amp config., as Paul suggests. And my other electronics are PS Audio!

[@sameerkhan2707]

Paul Are there commercially built phase inverters available? How does one achieve this without xlr outputs? Also what is the mechanism for writing to you to ask a question. Thanks

[@InsideOfMyOwnMind]

I won't answer FOR Paul but I will throw this out there. Some non-balanced preamps had both inverting and non-inverting outputs. If you have one of those you can just use one of each to drive the amp. Personally I would not try to bridge an amp unless I knew very well how it was designed to avoid any possibility of potentially self destructive rebellion from the amp. A certain amount goes into determining whether or not an amp design is suitable for use in this config.

[@marianneoelund2940]

You can use an isolator to invert signal phase, with a simple modification. These are commonly used in car audio, to avoid ground-difference issues. You will want a high-quality model. I bought a batch of different isolator models and tested them - there are significant differences in quality!

[@alanm.thornton4055]

Can you take two of the same stereo integrated amps, and use them for left and right channel use? As in two 60w integrated, feed left RCA signal to one, and right RCA signal to the other, with one speaker feeding from it's corresponding 'mono' amp?

[@jondonnelly4831]

Don't do it. It might work, it might damage the amps. Expensive experiment.

[@mrkrinkle8323]

THAT'S ALL I WANT TO KNOW! Why wouldn't that work? I have 2 ADCOM 535ll that I want to do this too. It's impossible to find info. Been looking for weeks

[@gtric1466]

My Onkyo is 100 watts 2 channels driven, 190 watts 1 channel driven. since there both using the same power supply and capacitators. you may want to look into your owners manual. but why do you want to do this is it purely for more wattage? would still need a 2nd amplifier.. i don't think it would sound any better. maybe if you have pre-outs and want to use your amp as one of the mono blocks but then they would have to match or use one amp for highs 1 for lows as in bi-wiring your speakers..

[@gyrgrls]

Remember two things: 1) There are three ways to do anything. 2) Even a compound bow has its drawbacks.

[@SLCVideoProductions]

Soundcraftsmen sold a phase inverter to do just what Paul described for some of their amps. I picked up their PCR800 from Ebay and built a simple inverter circuit and was able to get a bit over 400w into 8ohms from it.... Like seeing your "lab" area.

[@VOLKOV9]

Lol I want to know more about the drawings on the cardboard behind Paul.

[@izzzzzz6]

Where do you switch phase if all of the commons are shared? Oh, you must have XLR's and swap one xlr out of phase.

[@gyrgrls]

Seen on eBay: DIY Monoblock conversion kit - $29.95 Fire extinguisher - $24.95

[@ekanshmeena2788]

How to convert 4 channel amplifier in mono block🙏 please help

[@stimpy1226]

My Audio Research power amp. has a toggle switch on the rear panel to turn stereo into a bridged mono amplifier. I was toying with the idea of buying an identical amp and bridging both to get two mono amps with more power and control to my Maggies.

[@randys435]

My Adcom gfa 555 has the same bridge switch. My Mirage M-1's are bi-amped so I bought another gfa 555 amp to run them that way. However I found out the 200 watts was not enough power, they would clip at higher volumes. The solution was to use the bridge feature which gives 600 watts and run them as mono amps like you are considering. I have ran it this way for over 25 years with no problem.

[@stimpy1226]

@@randys435 Although the first Watt is super important, I don't believe that you can have too many Watts driving some planer and other speakers that need better mid-bass control the same way you can never have enough memory in a computer system.

[@marianneoelund2940]

That will give you about 3x to 4x more power - provided the amp can handle 2-ohm loads!

[@stimpy1226]

@@marianneoelund2940 8 and 4 ohms. That’s approximately 220 W per amp which is more than enough for my Maggie 3.6 R’s. Just the single amp I have now does a great job but I want to get a lot more headroom.

[@marianneoelund2940]

@@stimpy1226 You will need an amp that's rated for 2 ohm loads each channel, if you want to use bridged mode with the Maggies.

[@georgeanders6129]

How hard is it to modify a car amp to power a cb radio

[@alb.1911]

There are stereo amp that allow bridge mode with a switch and you can use it do bi-amp your speakers.

[@KeithMacRowland]

Using a stereo amp in bridged mode, which turns it into a single channel mono amp, has nothing to do with bi-amping your speakers. To bi-amp your speakers, you would need 4 active amplifier channels. You could use 2 stereo amps, or 4 bridged mono amps. I'm using my AVR stereo receiver Front Left and Right channels for the midrange/tweeters and taking the AVR subwoofer output to drive 2 bridged mono amplifiers to drive each woofer. It's easiest if the amplifier has a bridge-mode switch built-in.

[@izzzzzz6]

Can't you just put the two + wires together with a balance resistor network between them? Then go from the middle leg of that double high power low impedance resistor for the + and to the ground for the - ?

[@Baerchenization]

Here is an easy step-by-step guide: 1) Sell stereo amp on Ebay 2) Buy mono amps on Ebay

[@QoraxAudio]

Didn't we do bridged amps about a week ago? Sounds like Paul is stuck on repeat 😅

[@transkryption]

More theory? Yes Please and a whiteboard/ Talk about how underrated signal to noise ratios are in reproduction

[@graxjpg]

Knowledge of that ratio is hugely important for recording correctly!

[@ThinkingBetter]

Someone will blow their amp with these experiments.

[@AnOriginalYouTuber]

Already done. It was a cheap free one however.

[@ThinkingBetter]

@@AnOriginalKZbinr Free is sort of cheap 🧐

[@geoff37s38]

What’s a soddering iron?

[@Enemji]

🤣 Soldering = Soddering in the US of A

[@geoff37s38]

@@Enemji ahh yes. Mangling the English language. Such as the often used phrase in the US “I could care less” instead of saying “I could NOT care less”. I once accidentally picked up my soldering iron by the hot end and called it a “sodding iron”.

[@AnalogueGround]

@@geoff37s38 A lost cause - nowhere else in the world exists other than America :-)

[@joeythedime1838]

Paul's previous video about this: kzbin.info/www/bejne/nIi3coR5grFjgZI

[@josefbuckland]

Watt?

[@gyrgrls]

Relay, now!

[@chefchutardo5215]

Dual voice coil speakers would work. Unfortunatly ive only seen subwoofers that are dual voice coil.

[@colognearmy4506]

Surely you need to connect the 2 black terminals together.

[@marcusm5127]

Most often you don't they are connected internaly in many amps.

[@marcusm5127]

@Douglas Blake Not in a solid state amp. Open loop isn't dangerous for them. Shorting terminals is dangerous.

[@markclark1605]

Bridging amps causes the loss of bandwith.

[@Enemji]

How about - Take the output of Left channel and feed them to the input of the Right Channel. Now your power is multiplied 😬 ie Left is the PreAmp for the Right

[@Enemji]

@Douglas Blake 🤣

[@wallyboy529]

Sorry to spoil your fun there Paul, but the speaker has to be connected between the two red terminals . The blacks of both channels are always at the same potential (ground)

[@wallyboy529]

Agreed. But I think we are talking about run of the mill stereo amplifiers. Connecting as Paul describes will not result in a power increas

[@MustangBoss1973]

Paul I was fully understand img until you tried flying at 4:05

[@crispy_otter]

Bridged amps are ok until someone builds toll booths....

[@gyrgrls]

Sorry, no E-Zpass for these bad jokes...

[@chadbarker4023]

PS should build a version of the monster receivers from the 70s and 80s! Yeah I know , cost blah blah blah, but your stuff is already expensive so wtf! Do it. But can you build some speakers 1st!

[@dhpbear2]

This parallel arrangment would work with a tube amp, since they are basically current sources! :)

[@janinapalmer8368]

Tubes , transistor ? They are both current sources ...

[@marianneoelund2940]

@@janinapalmer8368 Not after you close the feedback loop.

[@marianneoelund2940]

No, even tube amps are voltage sources, but they do have higher output impedance, and that's what lets you connect them together - after carefully matching the gains, of course! But the only reason to ever connect amplifier outputs in parallel, is to handle speakers of lower impedance than the amplifier's rated minimum load impedance. I can't imagine that situation occurs very often with solid state amps; with tube amps, it could work well if you have the correct output taps.

[@jimcatanzaro7808]

Circuit design is Pp not Se

[@aakar88]

Ps Stellar (M 1200?) on the cover of the new issue of Stereophile!!!

[@kerrygeist1261]

Amplifiers don't like looking into each others output impedance...

[@nyccrcsx]

First

[@Mark-lq3sb]

21st, exciting!

[@nyccrcsx]

@@Mark-lq3sb great 👍

[@Mark-lq3sb]

@@nyccrcsx Thank You! Here every Wednesday... Don't forget to tip your waitress.

[@nyccrcsx]

@@Mark-lq3sb always do especially now a days

[@MrZeevG]

Sorry, Sir! You not give some think new. You have already thousand, like yours, videos explanation on many different channels. Minimum tell how practically to make one channel to opposite to another.