Bridged amps vs monoblocks

Stereo bridged amps vs. dedicated monoblock amplifiers. And check out our new KZbin channel, Octave Records / @octaverecordsanddsdst...

[@stephens2r338]

Most manufactures who make stereo and monoblock amps are basically the same if you open the lids. One of the big issues the designers have to deal with when bridging an amp is noise. 4x the power means 4x the noise.

[@chucktyler4057]

Thanks Paul. This is the same situation I've found myself in. Driving Maggies with identical bridged Hafler amplifiers. When I first tried this...wow! The soundstage opened right up. I've heard the naysayers but I know what I am hearing now compared to running bi-amped for years.

[@chucktyler4057]

Of course I'm looking at a 5 ohm pure resistive load and that was a concern initially. But amps seem to be taking it all in stride after a couple of years.

[@image969]

Best audio information I've ever got is on this channel. If you're equipment wouldn't result in higher payments that my mortgage I'd fully support you throughout my home with high end sound lol

[@benplachy2914]

dude same lol everything paul does is gold

[@snhongo1]

That was a good question it has been troubling me for a long time...couldn't find an answer to it in a very long time

[@bertoray5497]

I have two stereo amps bridged and recently listened to one of them in stereo mode. I then switched back to bridged mode, listened to the same songs, and was amazed (again) over how palpable the improvement was.

[@user-od9iz9cv1w]

That's great feedback. thanks

[@salvadorrodenas3071]

In which direction? That's no very clear for your comments.

[@bertoray5497]

@@salvadorrodenas3071 Sounds better with two bridged amps compared to one stereo amp.

[@faludabutt8253]

bertoray why did it sound better ?

[@salvadorrodenas3071]

@@bertoray5497 ok. Thanks for clearing any confusion. And if in your case it sounds better why it wouldn't be true? Nonetheless, why don't you try to biamp each loudspeaker with one stereo power amplifier, not bridged. One channel for mid-highs and the other for bass? It would be very interesting to test. Best regards!

[@mwrightinsurance]

I’ve always wondered about that, thank you! I run a bridged amp on my 8ohm center channel And stereo amps for the other six channels

[@adamk4716]

I have two stereo amps and there’s a switch to bridge each one into mono which I do. The manufacturer states in the manual that it increases the wattage by 1.8x. It’s a 50 watt stereo tube amp so I’m getting 90wpc now according to them.

[@scottfowler50421]

Great channel this is. I use the Marantz system cd player model 7300 with the brand new amp 8006 I play them out of my Wharfedales 11 series, model 11.3 loud standings Speakers, bi wired them with a Scottish brand called Atlas Colbait Bananas Plugs and I connected the amp with the Danish brand deli luxury Bananas Plugs. I didn't go to a high expense with hi fi cable's because they are a rip off through hifi shops here in the UK so I went to a normal electronic shop and bought the same type of cable as the QED anniversary bi wired. And I use QED Qunex Precision 1 interconnection to connect my cd player with my amp One of the greatest sound I have heard when I play all my music. Great channel this is.

[@robertschmitz4025]

Wonderfully and understandably explained!

[@RC-vy1vu]

Whompus is a great technical term, borrowing that one!

[@georgeageorgopoulos]

Paul, buddy, all same, bridged,monoblock,integrated,paralled,etc....GGA monohifi - Greek Audio ;))

[@joenogueira2801]

You forgot to mention that vertical bi-amp is a better alternative to bridging (no effect on impedance) and provides better headroom per channel. 🍷

[@JT-ny7ll]

Agree, if you have 2 identical power amps, each of which has enough power to drive both speakers, and so has ample power to drive just one of them, then vertical bi-amping with bi-wiring is a much better and lower risk option. The extra power from bridging is not usually necessary if you have the right amps to begin with. And with the vertical bi-amp & bi-wire option, each left and right and high and low channel is separately driven.

[@rom661]

Hi Pauls (know you won't see this). Of course you do need plenty of current delivery to bridge an amp. But my firs "real" system, 40 years ago was your early PS passive preamp w/optional active section (half space) with your matching phono stage. My amp((s) wre the little shoebox sized things of the day. I was running a pair of KEF 105's and ran them in bridge mode so instead of 40W I had 160W. Perfect, right? However one of the amps blew up (user error) and I sent it back to you for repair and put the single amp in 40W mode. Not enough power to really drive the KEF's but the sound was far superior. And I learned. I've been a high end dealer over 30 years now but have never forgotten than. Not all bridgeable stereo amps SHOULD be bridge. Some of them just work too hard into that lowered impedance, or the same impedance that requires the amp to deliver twice the current. Nice explanation.

[@user-od9iz9cv1w]

Lot's learned from this question. Thank you! I guess my other concern is the size of the power supply. I'd think stereo amps are built to a price point. They may have sufficient sized power supply, but may not be over spec as you might find in monoblocs serving more of a cost no object audience. And as Paul has pointed out, an oversized PS is a good thing for sound. I run 110w triode monoblocs. Each channel has 7 transformers. Some are for filaments, but the output is oversized. They sound great. Not easy to lift. Kind of the antithesis of class D. :)

[@saint6563]

Heard & believed last Century bridging could add distortion ['grain'] to the sound and was more for commercial systems. Even avoided doing so with two stereo amps driving two speakers.

[@roofpizza1250]

It's really common in car audio and many of the guys are damn serious audiophiles.

[@saint6563]

@@roofpizza1250 No doubt it add watts & car audio enthusiasts are even more power hungry than audiophiles in general. hahaha Not saying it's 100% true, hence the "heard & believed" to start off. However, making an amplifier produce more watts than it was rated for can add distortion. Would entirely depend on the design, build quality, & parts used. Again, not saying bridging is always the worse thing to do. As Paul stated the amp has to be considered before doing so & I would add the speakers as well!! Enjoy.

[@philiptong4978]

guess what happens if the drivetrain (or a left/right differential) bias torque delivery to one side of a vehicle

[@salvadorrodenas3071]

@@roofpizza1250 in car audio is a necessity because the maximum voltage available from the PS of the car is 12 volts max.

[@budgetaudiophilelife-long5461]

🤗 THANKS PAUL…FOR BRIDGING OUR KNOWLEDGE 🧐😍😍😍

[@gillgrant5559]

On a serious note, if you have two stereo amps to use as mono blocks, might be better to join the input channels (Left plus Right), combine the output "hot" terminals each through 0.5 Ohm resistors. Connect this point to speaker hot and cold to speaker cold. You will not quadruple or even double the power output but the output impedance will be reduced as both channels are working together. Should give a better sound rather than a louder sound which is want we all want right? It wont burn out the power supply in the amp either. If you have one of those nasty balance controls ensure it is kept in the centre so both channels output the same level.

[@spikeogat7688]

Hi Paul I have a question that I want to ask you. what is it called when connect two amplifiers with RCA in and out with each having there own speakers?

[@LuxAudio389]

Paul returned from visiting his mistress in listening room 2😉

[@lawrencebishton9071]

Reminds me of the stage hotel 🤣

[@ridirefain6606]

I use tube amps that are designed to run in either a mono or stereo. They drive my albeit very efficient but still a 4 ohm speaker just fine. In this configuration, I have something that gives full and natural sounding vocals, with powerful bass that is clean and tight. In short, no problems running these amps into a 4 Ohm load.

[@salvadorrodenas3071]

I don't like how bridged stereo amps sound. Besides, the current capacity is halved while the voltage is doubled. Not a good idea is you feed a low impedance loudspeaker. Very good video!!!

[@philiptong4978]

without changing power supply to each single ended channel, bridged mode should result in same max output current and doubling voltage by the reverse polarity amplification (the negative terminal is no longer at 0V)

[@salvadorrodenas3071]

@@philiptong4978 no! The negative terminals continue to be 0 volts, it's the ground. What happens is that you don't attach the speakers with those terminals but between two live posts each 180 reverse degrees and the load is connected to them.

[@philiptong4978]

@@salvadorrodenas3071 I meant the negative terminal at the speaker, sorry not qualifying it

[@philiptong4978]

the term phase has a time component associated with it, since it make sense for both speaker +/- terminal to be in sync (by time), it is clearer to use the term polarity instead, the cold wire is supposed to carry the same signal as hot, same phase, just reverse polarity

[@salvadorrodenas3071]

@@philiptong4978 that's it!!!

[@heshamsalah251]

Hello paul, I have Yamaha RX-A6A and power Amp Emotiva is it possible use preout with powered in the same time Example ( Powered Front L&R to speaker and preout front L&R to power amp ) Thanks in advance

[@ekimandersom4478]

no

[@CraigFlowersMusic]

Does this also apply to small, single-ended triode amps? Because my plan is to get some of those new Jubilees which are like 108dB@1w/m each, and run them with a 3-5wpc single ended amp. Seems like there would be no reason, in that particular case, to get a pair. Right?

[@woohunter1]

Use dual stereo amps and bi-amp.

[@tonyklothos7093]

Love your videos! Just one question: how does it feel sitting on a comfortable couch, in what looks like paradise? Ha, ha! Kidding…OK, maybe not!

[@lawrencebishton9071]

Phish n chips merchant

[@mvsrpharma]

🐤

[@centerfresh8472]

In case of bridging, why 4x times the output power? Shouldn't it be doubled, I mean 2x times the output potential? Am getting a little confused here..

[@stug77]

I think he may be saying that because of the impedance change. Lower impedance means more watts are needed for a desired voltage. So you're getting double the "audible power" but quadrupling the actual watts being pulled.

[@boblehman1726]

The load (the speaker) remains whatever it was, unchanged, not doubled or halved or quadrupled. The voltage out of the bridged channels is double what it would be from a single channel. Power = voltage times current, OR voltage squared divided by the impedance, OR current squared times the impedance (simple Ohm's Law equations). IF the amp has the ability to maintain the doubled voltage to the same impedance (i.e., a hefty power supply, enough capability in the output devices, enough heat sinking), then the current will also double. Double the voltage and double the current to the same impedance would then result in 4x the power (2 x 2 = 4, 2 squared = 4). These are maximum possible numbers - depending on its design, any given amp may not be able to achieve or maintain the quadrupling of maximum power before blowing internal fuses or overheating or burning up! For these reasons, some bridgeable amps may be specified to only be able to drive a higher minimum impedance in bridged mode compared to normal stereo mode, e.g., 8 ohms instead of 4 ohms.

[@johnnytoobad7785]

Bridging has risk when the power demand is high (the PSU may fail..) and when the power demand is low. Typically there is higher crossover distortion in bridge mode than UN-bridged mode (unless you can tweak the bias circuits). "Bridging" is more of a marketing gimmick than anything else.

[@marianneoelund2940]

As an engineer, if I'm designing an output stage with bipolar transistors (BJT), it's far easier to achieve high power with bridged channels that will be operating with lower power supply voltages. Those lower voltages are a huge help in avoiding device secondary breakdown, which is destructive. But bridged mode is most common in car audio, live sound and commercial sound systems, where high power has priority and distortion is a lesser consideration. In those applications I would not consider it a marketing gimmick. In audiophile applications, you are correct that crossover notch distortion will be more apparent; it is unfortunate that few manufacturers specify distortion at low power levels where this matters most, and where we often listen to our music. As long as users understand the effect of bridging on load impedance, and are aware of their amplifier's limitations, there need be no concern about damaging the PSU or output stages. But it's true that many owners never read the manual, and people do the darnedest things with their equipment at parties when there are few sober people present.

[@johnnytoobad7785]

@@marianneoelund2940 very true. Great analysis.

[@lawrencebishton9071]

Called flapping a b out a bout of hill ness monos tier for three

[@bakeone4406]

Wise man say, make sure your amps have a high enough "whoompus" rating before trying to bridge them.

[@robh9079]

To muddy the waters; there are some stereo PA's built dual mono with 2x transformers, saving on buying another chassis - and chassis are expensive. driving bridged with balanced i would think makes good sense as you have a ready made inverted signal for one channel - which is what schiit have done. (please correct if i'm wrong) musical fidelity do a dual mono using one transformer with 2 windings - a bit of a compromise though a good economy.

[@philiptong4978]

mono block > dual mono (independent power supply) >> shared power supply

[@robh9079]

@@philiptong4978 think its the MF Ms5i that has the dual mono with separately wound 1/2s of the transformer, and didn't mention has completely separate psu circuitry beyond the transformer. Would proffer this is much closer to independent power supply than shared. next model up has the 2 transformers. $ for $ a dual mono is likely better than mono block, as chassis are expensive, and 1 less chassis could fund fund a serious upgrade to parts quality, including expensive parts like transformer and power caps.

[@christophero1969]

A wiring diagram would have helped.

[@hugobloemers4425]

Google images: "Bridged amplifiers"

[@normhiscock352]

Do you think you'll ever branch out into car audio?

[@allansh828]

is that an Innuos server?

[@lawrencebishton9071]

Skitso effect hive diss order resolved by paying i.t to me or tradeing it for Same value in pounds lbs

[@edd2771]

Paul your explanations are always excellent but you lost me on this one In describing what a bridged amplifier is. It sounds like inverting the phase would cause the speakers to get the wrong signal. I know im missing something, but maybe revisit this topic at a higher level for the crayon set (like me)

[@Christian-op1ss]

Hi Ed, it is indeed a bit confusing, as having speaker signal out of phase is in indeed a bad thing. The phase inversion Paul discusses is something that only happens inside the amplifier. The resulting output is still in phase. The phase inversion is used in bridged amplifiers to take a signal and split it across two amplifier channels. This way, when in one channel the signal goes up, in the other channel it goes down by the same amount. If you then connect a speaker to only the + (hot) outputs of those two channels, the difference of signal between the two will again be in phase, but amplified.

[@edd2771]

@@Christian-op1ss thank you. So what is the benefit, and if the signals for the channels are reasonably parallel over any length of time is there any benefit at all?

[@edd2771]

@Douglas Blake that’s helpful thanks.

[@gillgrant5559]

Married people should never use monoblock amps. In the event of a divorce you will both end up listening in mono. (assuming you each got one speaker).

[@AccuphaseMan]

I assume you can't do this "manual" bridging with a dual mono differential amplifier.

[@philiptong4978]

take the hot balanced signal, derive a new balanced pair (now each wire has 1/4 level of original unbalanced), feed the mono diff amp #1 with unbalanced out repeat the same with cold balanced signal, feed it to mono diff amp #2 with unbalanced out Amp #1 unbalanced out send to speaker +ve terminal, amp #2 unbalanced goes to same speaker -ve terminal

[@manmeetjammu]

4:26 ????? 🧐🤔 Any body plz. How 4 ohm becomes 2 ohm . I mean drivers.. Plz did not get it at alll...

[@InfinitygamingFtw]

What he's saying is if your trying to take an amplifier where the minimum impedance of it's output load is 4 ohms and you wire two of them in in parallel then if you connect a 4 ohm load(speaker) to them, each amplifier only has 2 ohms of load which is below it's minimum impedance which can damage the amplifier by drawing more current then it was designed for. So if your bridging 2x 4ohm minimum amps you need an 8 ohm minimum load so when it's wired in parallel each amp gets 4 ohms load.

[@boblehman1726]

That statement was incorrect. The speaker impedance (resistance in simple terms) is what it is - it doesn't change depending on the amplifier driving it, or the configuration of the amplifier. Bridging a stereo amp doubles its maximum POSSIBLE voltage output compared to using each channel individually. IF the amp design has the capability in its power supply and output devices, then the maximum POSSIBLE current will also double, and since power = voltage (V) x current (I), the maximum POSSIBLE output power would then quadruple. // If we want to bring speaker impedance (complex resistance) into this discussion, it will get more complicated. Suffice it to say that, as defined by Ohm's law, for resistance (R), I = V/R, i.e., for a given output voltage and a given resistance (or, if you want to go there, impedance Z, which is complex resistance, which includes the effects of capacitance and inductance), the current that will flow is the voltage divided by the resistance. Hope that helps!

[@manmeetjammu]

@@boblehman1726 Thanku very much. One more request. I am building two Speakers. 3 Way with drivers being 60 watt Aes ( 150 hz to 800), 40 Watt Aes (800 Hz to 3000 Hz), Tweeter 3000 Hz onward (All 4 ohm Drivers). I hv an Amplifier with 4 channels with 60 watt RMs output for each channel at 4 ohm. But in bridge it can do 150 Watt in two channels( Courtesy Manufacturer). I have a Subwoofer too which is rated at 250 watt RMS at 4 ohm. Now what should I do. Use bridge for Sub and mono for my Two new Speakers. Or bridge for Two new Speakers and buy another Amp for Sub. I am not a loud listener. Thanks for the ans in advance.

[@jeremiahchamberlin4499]

@@InfinitygamingFtw Very good explanatio -Now I get it, finally. Thank you very much. 👍

[@marianneoelund2940]

@@boblehman1726 Paul's statement was correct. Each channel of the bridged mode amplifier "sees" only half of the load impedance. If you put an 8 ohm speaker across bridged amp outputs, each channel has to push out the same current that it would with a 4 ohm speaker. People get into trouble all the time, with 4 ohm speakers and bridged amplifiers, because each bridge channel is effectively driving a 2 ohm load - which may be beyond its design limits.

[@akhtarizod5802]

Output impedance of an amplifier in bridge mode doubles and damping factor cuts in half ! Not ideal to drive low impedance speakers!

[@HiFiInsider]

bridged amps is not as good if they aren’t closely matched.

[@markclark1605]

My understanding is you loose your bandwidth briding amps.

[@marianneoelund2940]

Not unless the amplifier has less bandwidth with lower-impedance loads. That should not be true in most cases. But you do lose some signal quality at low power levels, due to increased noise and crossover notch distortion.

[@scottdc6971]

I’d take an SE amp over a BTL all day everyday

[@marianneoelund2940]

On the other hand, bridging SE amps is a good way to eliminate even-order distortion harmonics.

[@lawrencebishton9071]

Stinks

[@graxjpg]

I had some nice monoblocks. until recently, when my wife split, she took everything of any value. Not like it was much, but I wake up in the middle of the night every night covered in sweat with that shit on my mind.

[@bassedtaz]

Could be worse, she could be still around. Worth a couple amps to be rid of someone who would steal a couple of amps. Impeccable logic I know.

[@roofpizza1250]

Better to be single and miserable than married and miserable I figure.

[@philiptong4978]

kzbin.info/www/bejne/pKHImoWwrsyiZ9k

[@graxjpg]

@@roofpizza1250 great points all around. I wish I could convince myself of them.

[@pioneernut7487]

Dude next Time dont make this mistake....

[@lawrencebishton9071]

Plastic smell

[@lawrencebishton9071]

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