Is the Reverb useful, or just a gimmick? Philips Reverbeo B7X14A Stereo restoration pt 4

[@GeeWillikersMan]

My brother had a 65(?) GTO that had reverb on the car's radio. I always found that interesting.

[@electronicsoldandnew]

👍

[@geirendre]

Nice thing that it actually worked. Don't think that they tried to create any "stereo effect", it's rather an atempt at creating the echoy sound you would get in a large room. So more of a "Hall-effect" much like what you find in modern surround receivers. A gimmick back then and a gimmick today.

[@electronicsoldandnew]

True. Interesting, but ... gimmick, as far as I'm concerned.

[@goodun2974]

First of all, although the reverb tank measured the same DC resistance on both coils, the actual impedance at audio frequencies is probably more like 1K to 2K ohms, and the 2 transducers might actually have different impedance characteristics (one might be optimized for spring drive and the other for audio pickup), therefore it is always important to hook up a reverb tank the correct way around, whether it is in a radio like this or in a guitar amp. In this case, the reverb delay time seems very short, which is a function of the resonant characteristics of the springs that were factory installed. If you have a code on that tank, typically starting with a 4 because it has 4 differing springs, you could look it up online and find out what the impedances are and what the delay time is (short, medium or long). It does sound as if the tank is being hit rather hard from the driver circuit and it might sound better if you are able to reduce the drive gain.

[@electronicsoldandnew]

👍

[@paulbennell3313]

It was 15 years ahead of it's time. It's got a dub reggae button! Got to love that!

[@greggaieck4808]

Electronics old and new your utube videos are awesome and interesting

[@electronicsoldandnew]

Thanks 👍

[@maartenschapendonk6345]

I think toccata en fuga will sound great with that effect

[@electronicsoldandnew]

I'm sure it will. That piece needs the re-creation of a large cathedral echo :)

[@eliedelorme9945]

I can tell you, I just received today a big heavy package and guess what was inside ? A brand new refurbished Philips stereo Reverbeo. So excited to open it and listen to this legendary Philips radio. Believe me this thing is huge with great proportions. I plugged it on 220v swith it on with the right knob, plugged an efficient Fm antenna press the Fm selector and Connected « France Musique » stereo Channel thé red light up right hand side lighted up and I can tell you that the stereo operates properly. The sound that this elegant beast in ors varnished dark oak cabinet is purely astonishigly magical ; précise deep clear warm round detailed. I have many hifi system Quad, B&O but this Philips is way ahead, it is due to its ten tubes valves and its 2 big 800ohm loud speakers. My hifi system will stay of for a while. This is a grateful caress to my ears. And the reverb effect is improving the sound. When I am in the room I can’t tell where thé sound comme from it is all around you, believe me it is something everybody should experiment once in the lifetime. So delicious even orgasmic. Only for initiate and passionate !!!

[@electronicsoldandnew]

Enjoy your new passion 😊 Most people don’t believe in the magic of the sound that one of those radios produces. You have to listen to it to understand, as you do.

[@haraldlonn898]

When I was young we had one of these Philips with reverb. Fun useless thing, tested it but never used it so it was a waist of money to buy the radio with the reverb. Thanks for nice videos. /HAW

[@electronicsoldandnew]

I agree that the reverb is really a gimmick and was probably never used by the owners of these radios.

[@greggaieck4808]

Electronics old and new your phips reverbeo streo this is so awesome

[@alfredneumann4692]

The Reverb (in Germany we name this Hall) is easy destorting by overload. Yes i had one in hands in the 80s in a guitar-amp. Later they inevented the bucket-chain-memories. I don't like these helical-springs. But it was nice to see one again. Thanks.

[@electronicsoldandnew]

My pleasure, Alfred.

[@ricardoaliasdelatorre6836]

Manuel is just an emulation concert hall, jazz club,... With the "State of Art" at that time, its fun, & you have restored it quite fine. Obviously a solid state or little Dsp would win the party but... with no "Original" taste

[@electronicsoldandnew]

true 😊

[@jhallo7740]

Nice video. I had in the past many of this kind of philips tube radio's, also this one. The reverb strength can be controled by the balance pot, but also than, it's not a pleasure to listen to. Maybe some "talk shows" can benefit from a little reverb.😄 Later types as the B8X44A has also reverberation units build in, but than a lot smaller. They have reverberation on both speakers, this B7X...types on one only. It was a gimmick back in the 60's from philips, and they came with this "luxury", with a bigger pricetag.😄 For me, the best addon to tube radio's in the 60's was "FM STEREO". My B7X43A has this feature, and is really a pleasure to listen to. And yes, this radio has also the big reverberation spring at its back, but i never use it...Keep the good work up.👍

[@electronicsoldandnew]

Thank you 👍🏼

[@torugonza]

Recuerdo haber reparado esos resortes en amplificación para guitarras

[@electronicsoldandnew]

👍

[@sincerelyyours7538]

Interesting effect the reverb unit has on music! Immediately reminded me of a dance hall and my ballroom dancing days as a young man. Before the internet grabbed everyone's attention and made us all shut-ins people actually socialized in dance halls. My grandparents danced to live music in the 20s and my parents danced to radio or vinyl records in the 50s, both in whatever dance halls their towns could provide which was usually churches or school gymnasiums. The acoustics of such places were probably terrible so the reverb unit fitted right in. At least that's my guess.

[@electronicsoldandnew]

Yes, I guess reverb was part of the experience then. There was no time or money to treat the walls of these places to prevent reflections.

[@professormicron6470]

I have a Grundig console that came equipped with a reverb unit. I haven't done any work to it yet cause the chassis is practically impossible to access without taking most of the thing apart and I don't have the space to do that right now, so I can't share any listening experience yet. However I was lucky enough to get the instruction manual for both the radio chassis and the reverb unit and i've read what it has to say. I've also done some digging online. So the primary function of the reverb was to simulate the delayed sound reflection in large concert halls. There is a desired amount of delay that concert hall designers consider to be optimal (something around 1ms). Simulating that was supposed to enhance your reception of some types of music. I guess it could work with classical music. In this context it's a little bit weird that it only works in mono on Philips. I imagine it would be most useful when playing records, so why not in stereo? Grundig's system seems to work in stereo (although the reverb component of the output would be the same on both channels as there is only one reverb unit) and it also lets you adjust the reverb strength, so you can turn it down a little

[@electronicsoldandnew]

I will only really get the feel for it when the cabinet is done, so it’ll be interesting to play around with it then.

[@heavenplus1]

Lovely video. I am in early twenties and I have never heard of this technology or gimmick or whatsoever. Very informative and interesting video. Thanks for the upload.👍

[@electronicsoldandnew]

My pleasure

[@tobi8496]

With the balance pot you can regulate the reverbeo effect.

[@electronicsoldandnew]

👍

[@chrisclark6192]

Hello again Manuel. Well done getting it back to the original condition. I think the reverb sound is to try and imitate a live performance to the music. It reminds me of the concert hall setting on my mp3 player. I think the sound from the reverb may improve when everything is back in the cabinet. This really has been an interesting restoration so far, and looking forward to seeing and hearing the final results. I was wandering if there was any way of variating the effect of the reverb. Cheers Chris.

[@electronicsoldandnew]

I’m also looking forward to hearing it in the cabinet, and adjusting treble and bass settings to see how it sounds.

[@erikdenhouter]

Input transducer and output transducer, that is how they call the elements from the reverb tank. It makes reverberation, like the sound in a closed space with hard walls, and that is a repeat of the input sound. What you tried to mimic was a tremolo as on a guitar amp, a low frequency volume wave. In between the poles of the two electro-magnets there are two little magnets on these springs, four in total. They act like a speaker (the input) and a pick-up coil (the output). I hope we can enjoy this after this repair, it is after all a bit special for a (mono) radio, and I also wonder how it is implemented for the stereo input.

[@erikdenhouter]

Ah, I reacted before the end of the video... Heard it. Now we know why this is not continued 😂

[@electronicsoldandnew]

👍 😊

[@chriswade7470]

I think the reverb is only meant to be used with a monophonic sound input. I had a surround sound processor ( my first) which used to make old 1930’s 78rpm Opera recordings sound very lifelike.

[@electronicsoldandnew]

👍

[@DavidTipton101]

Hi Manuel, well the reverb works and I guess it will create a hall effect, is there an attenuation control or a filter to knock off the lower frequencies? It seemed to cancel out the low end. That was a very interesting watch Manuel. That box would now be replaced with a small chip with many different effects I guess. Cheers 🙂

[@electronicsoldandnew]

The filtering is minimal, strangely enough (unless I’m missing something again🤔) I agree, these gadgets got so small you could hide it behind a resistor in there 😊

[@ry491]

Hi again Manuel . The reverb works best only when chassis is in cabinet and back fitted . It's fantastic on speech. Sounds like people are in the room . Music not so good . Can sound a bit muddy . Not great on AM I find . I have it on very low for music . You have done really well with that radio . Mine nearly got thrown out of the window a few times !! Got there in the end though . Typical Philips isn't it . Have you noticed the silent on/off function . Nice touch . No thump as you switch off ... Regards from Thomas

[@electronicsoldandnew]

Yes, this one can test one’s patience 😊

[@nigelbrockwell6237]

Like you I wanted to hear what the reverb sounded like. At that time I think it was a selling gimmick, but might depend on the type of music played. When you have it finished and the speakers are facing forward, it might sound better. Glad you got that reverb wired up and no faults with the reverb pick-ups coils. This is the sort of sound you would expect in a Cathedral.

[@electronicsoldandnew]

True

[@alendubri]

Ok.. this was normally used as guitar effect, this is the sound of a real spring reververation! I didn't know that it was included in old radios!

[@electronicsoldandnew]

👍

[@goodun2974]

Here in the US I have seen old stereo consoles that had reverb built-in, both tube type and solid state units. In the late 50's Fisher sold an add-on spring reverb system for use with their stereo equipment. My brother had a Chrysler or Plymouth convertible that had a reverb tank in the trunk, feeding the rear speaker.

[@electronicsoldandnew]

Interesting that these were so popular.

[@JWimpy]

I have always loved playing around with reverb units. I have owned several different models. Back when I was in High School in the 1960's there were reverb units that mounted in automobiles attached to the car's radio. And every time you went over a pothole or railroad track there was a loud crash of spring sound throughout the car. It was quite the conversation piece. In the 1970's I bought an expensive reverb component unit that attached inline between the stereo receiver and amp. I always thought it gave classical music the sound of being in a cathedral. But they are not great for all types of musical instruments. Some instruments should not reverberate in my opinion. I once connected one through our telephone and made a call to a friend. It sounded like I was calling from inside a big cave. We all got a big laugh out of it. And, of course, this was back in the time when we were not allowed to tamper without a home telephone in any way for fear of a huge fine. The entire phone system, including the home base unit, was the property of the phone company.

[@electronicsoldandnew]

I remember well those days. The things we played with 😊

[@JWimpy]

@@electronicsoldandnew Yeah, but you are not old like me.

[@DimRoditis]

Captain Crunch times!

[@electronicsoldandnew]

😊

[@AlexK-vy3tt]

Hi, I thik you should sligghtly dampen springs of this reverb. For example put a little piece of some soft foam material under these springs. I know some old professional reverbs with springs layed in an oil tank, from Orban for example. Sincerely, Alexander

[@electronicsoldandnew]

I'm going to wait until the radio is back into the cabinet before I really judge what the effect sounds like. I'm sure it will be different.

[@goodun2974]

Organ "tone cabinets" (the first mass-produced powered speaker cabs) sometimes had oil-damped reverb springs. Don't forget that it was Hammond Organ that patented the spring reverb tanks of the type you see here.

[@timbeaton5045]

Think those brass coloured end caps are just there to anchor and shield the termination of the springs. I think you'll find that there are small magnetic slugs attached radially around near the end of the spring suspensions, so that the slugs are the parts that move in the variable magnetic field produced in the driver "transformer". Same at the other end, but in reverse. Note of course that the termination of the springs also force the sound waves generated in the spring to reflect back along the spring length which bounce from one end to the other, and decaying exponentially depending on how lossy the spring end points are (as well as other frictions in the spring, Thus the Reverb effect.

[@electronicsoldandnew]

Yes, that makes sense. Thanks

[@goodun2974]

The little "hooks" inside the metal tubes, that the springs connect to, are magnetized; one set of transducer coils drives the strings with audio to make the springs vibrate, and the transducers on the other end generate a corresponding audio-signal voltage but with numerous delays and reflections. The tubes sticking out the back are made of nonmagnetic brass.

[@andrewmcintyre8491]

I've worked on reverb units on spinet Hammond organs. Outside of certain musical instruments, I don't see the purpose for radio. It's a pity that there isn't an adjustment for the 'depth; of the reverb. With slightly less reverb, it might sound better. Try playing some regular hammond organ music through the unit and see what it sounds like.

[@electronicsoldandnew]

That’s an idea. Could be interesting.

[@electrosoundaust]

Hi Manuel, the lengths record producers went to get the reverb on vocals was rediculous in the 1960s. Toilets, breezways, long drainage pipes, asnything with an echo. Strange they didn't put two units in for stereo, I could understand that for a "concert" effect on church, chamber, or similar music. And AM medium wave is very important here because of the distances and emergencies. FM and DAB+ don't cut it in a major bushfire. So it will probably still be around in 100 years time.

[@electronicsoldandnew]

👍

[@goodun2974]

A plate reverb system can be the size of a small room and weigh hundreds or thousands of pounds. FranLab was playing around with a borrowed one a couple of years ago. There's also a video on KZbin of a guy who made a plate reverb out of a cheap metal shelf unit!

[@electronicsoldandnew]

👍

[@jutukka]

Yes, that reverb and the transistor seems to work exactly as it is supposed to work. It is not hi-fi, just a gimmick. The fact that the tank wasn't damaged after so many years shows how well built those tanks were in those days. They were made to last. That tank would probably give a nice wet surf sound in a guitar amp. Nice. 👍 P.S. The output side of reverb tank is very prone to receiving hum and buzz from transformers etc. because the signal level is very low. The problem can be reduced by shielding that area of that very open reverb tank better by metal shielding.

[@electronicsoldandnew]

👍

[@dirkk792]

Yess .... this is not Hi-Fi ... actualy all the Philips radio's from that eara ( the plano series ) sound like shit ! If you compare these radio's with German radio's from the same period & price they sound realy bad..compare with a telefunken opus, siemens schatulle, Saba Freiburg etc ..Big difference !

[@electronicsoldandnew]

As regards the freiburg, I’ll not argue with you 😊 My Freiburg is still the greatest sound I’ve heard from a tube radio.

[@ruawhitepaw]

It probably sounds better with certain types of music than with others. But I have to wonder how many people actually used that feature back in the day...

[@electronicsoldandnew]

Probably very few 😊

[@vicmabus1532]

Back in the olden days, you could buy a car reverb unit to mount under the dashboard to affect the rear speaker. Always sounded better with less reverb.

[@electronicsoldandnew]

And hear all the bumps 😊

[@vicmabus1532]

@@electronicsoldandnew Yes, railroad crossings were brutal!

[@electronicsoldandnew]

😊

[@radio-ged4626]

I like any gimmick that is clever but simple. The reverb ticks that box for me. Although really it's no different from any other transducer. Transforming one form of energy (electrical) into another (mechanical) and in this case back again with the properties of the springs affecting the output. Interesting to hear the effect.

[@electronicsoldandnew]

👍

[@goodun2974]

The "Look Mum No Computer" channel featured a reverb speaker a while ago that had springs mounted in front of a Philips speaker, which mechanically vibrated in interesting ways when music or signal-generator tones were played through the speaker. The springs didn't have any transducers or anything electrical actually attached to them, they merely vibrated sympathetically with the sound coming from the speaker. The thing sounded awesome, way better than you would expect. (PS, also check out the same guy's other channel, " This museum is not obsolete".)

[@electronicsoldandnew]

Thanks for the tips. Always interested in channels I’ve not seen before.

[@Timothycan]

I'm wondering if the reverb might have been popular with people who wanted to use this set as a home practice amp for a guitar?

[@electronicsoldandnew]

It's certainly a possibility :)

[@josealeixes2861]

Tá ficando bom parabéns…

[@electronicsoldandnew]

obrigado

[@tubeDude48]

I really like the reverb sound...but is was nice on some music, and over-driven/harsh on other music.

[@electronicsoldandnew]

Yes, I'm sure the type of music will make or break the effect. So far I'm not really a fan.

[@Theoobovril]

Manuel, is there no direct control over the amount of reverb you can apply.

[@electronicsoldandnew]

I believe you can use the balance control, as the reverb only comes out of one channel.

[@mackfisher4487]

Install your Bluetooth circuit, then use a Bluetooth pick up on your guitar turning the receiver into a guitar amp. Is this the only receiver you know of that has a reverb tank, it's too bad we don't have more of an understanding of the RF engineers who they were and what products they help to produce.

[@electronicsoldandnew]

That’s probably a very good use for it - the guitar amp. 😊

[@Cornz38]

Have you ever seen what the Beatles used for reverb??

[@electronicsoldandnew]

Nope 😊 must have been something awesome

[@Cornz38]

@@electronicsoldandnew It was an entire room with a similar spring configuration stretched from one end of the room to the other.

[@electronicsoldandnew]

👍

[@danielsaturnino5715]

Well that settles it then! I'm sure the owner wants a guitar jack in there somewhere :) Seriously, its just too much isnt it? It could be used if it could be tamed. Just my opinion anyway.

[@electronicsoldandnew]

Guitar interface, as I've done before :)

[@JacGoudsmit]

Yes the reverb is a gimmick. But most modern receivers come with a few similar gimmicks like dsp "concert hall" reverb and junk like that, that you only use once and then never again. And the Philips radio at least still has tone controls, which are oddly hard to find nowadays and (at least in my mind) were not a gimmick at all.

[@electronicsoldandnew]

👍

[@michaelmacdonald3408]

I think the reverb would be ok if you fed a guitar through the amplifier that's if the preamp will work with what ever guitar pickups.

[@electronicsoldandnew]

👍

[@donhall2759]

Sure, reverb is a "gimmick", but if it's controllable (as another commenter states) it's harmless and kind of charming. Might make it more collectable.

[@electronicsoldandnew]

👍

[@eddys.3524]

Nice gimmick that reverb... however, reducing it's effect would give a nicer soundscape...

[@electronicsoldandnew]

your probably right

[@greggaieck4808]

Electronics old and new my dad had a reverbeo hook up to his van radio when I was a kid when my mom and dad wore alive mom and dad are ded

[@horatiohornblower868]

That reverb sound is simply awful. No wonder it was disconnected.

[@electronicsoldandnew]

😊