The AM Forum

Hola,

I'm thinking of adding a wee touch of reverb.  I have a couple of those cheap digital units that sound terrible.

I understand the real spring units are the way to go to get the best sound for high quality voice work. Is this true or will the modern higher quality digital delays do as well?  I see a number of spring units on eBay going for anywhere from $120 to over $1000.   Any opinions?

Rich/ K1ETP and I were discussing them the other day and he said he liked the spring ones better - and referred to how good Chuck/ K1KW used to sound with a spring unit back in the 70's.

BTW, if anyone has a working self-contained spring unit (not just the spring tank) for sale, please let me know.

Thanks.

Tom, K1JJ

Wait until 10 opens and you can be heard short and long.

How about 50 feet of PVC pipe.

Spring reverbs have limited response and a fixed amount of delay. In general they suck compared to any decent digital box.

I like the way Kevin, wb4aio had his set up in the 80's. Not sure what type reverb he used, but
but it seem to only reverb on the highs, and there amout of smoooth decay on it. I have a feeling he
 split the audio up and reverb just the highs and mix together back with dry  and used some compression and peak limiting.

I had a factory spring reverb for the rear speaker in my '65 Imperial convertible.  It sounded like hell, and made all kinds of dramatic noises when I went over railroad tracks  ;D

My daughter spied a Hammond organ at an antique shop a few years ago and it ended up coming home with us; it came with the optional spring reverb unit.  As others have said the reverb section has limited frequency response and it doesn't have to be mounted in a car going over a bump to get some interesting audio effects. 

I would definitely vote for digital if you really want reverb (are you REALLY sure you want to do this???)

Under anything but perfect conditions this is going to take you into the more difficult to copy realm.  It will make your audio sound different from the crowd-but so will adding a bit of ripple to your bias supply  ;)

JMHO

Rodger WQ9E

I never saw the commercial spring units used on A.M. 'bcast. I heard that they were very big? Usually at the TX site. The ebay units are from that era?
I'll agree with the $200 Alesis digital, very nice effects. You can sound like the evil forces with the delay.

Fred

I have a Pioneer Spring Reverb Box....This is a high quality unit made for home stereo units in the 70's...It uses a flat metal spring about 6-7 inches long that is suspended horizontally inside the wooden cabinet.  It is mechanically adjustable for amount of reverb gain with a front panel knob..It has a lighted display window on the front panel that uses 2 intersecting triangles to indicate the amount of reverb being used.  I have been using it with the Gates BC TX.  I turn it on and leave the reverb gain at zero..I have it sitting on top of the transmitter cabinet and it picks up enuf vibration from the transmitter cabinet to provide just the right amount of reverb...It has send and receive jacks out the back and I plug it into the Behringer vx-2000 aux input/output jacks...works great...If I advance the reverb gain knob even a little, it goes into "haunted house" mode..Lots of fun to play with.  Most times no one really knows it is on but I get comments about "full audio" etc..I also have a guitar unit that is mechanical...I gave it to another ham but he hasn't put it on the air..Never tried a digital waa-waa box...

I have had a couple of spring reverbs, and yeah, unless used very sparingly they don't do as well as what I have heard from digital counterparts.

One was a Fisher "SpaceXpander" and the other was from a Hammond PR-40 speaker cabinet or a Leslie revolving speaker cabinet, usually paired with a B-3 or somesuch. For a while I was into Hammonds and their speakers, but they were incompatible with apartment living.

(http://photos-d.ak.fbcdn.net/hphotos-ak-snc1/hs026.snc1/3134_1151579310884_1269682876_399229_3134307_n.jpg)


I once picked up an AKG BX-15 at a state surplus warehouse. Now that was a whole different animal. Sounded GREAT and I wish I had kept it, but, like so many things, I wasn't using it and moved it along to a musician friend who could really do something with it.

Why not build yourself a plate reverb?  Still uses springs, but the metal plate shapes the twang.

http://www.platereverb.com/manuals/Plate%20Construction.pdf

History of the plate reverb (interesting reading):
http://mixonline.com/TECnology-Hall-of-Fame/EMT-140-reverb-090106/

Tom, this was from Jim Hawkins web site thought it was interesting.
Joe

THE BIG SOUND! HOW WAS IT DONE?
Remember the unmistakable reverberation on the sound of WABC? Well, at the time of these photos it was mechanically done with a large metal plate suspended by springs! Jonathan Wolfert, President of JAM Creative Productions, identified it as an "EMT plate reverb unit".
(JAM produces radio jingles and if you go to their web page by clicking on JAM above, you can order copies of past and present radio jingles.)

In a front room at the transmitter site behind some of the equipment was a big wooden box the shape of a small bed mattress, containing a mechanical plate reverb unit. The mechanical vibration from the signal was mechanically applied to the metal plate at one point and sensed at another with electrical "pickups" with a resulting added reverberation. The reverberation was mixed only to a certain extent to create just the right amount. The decay time was controlled by a mechanical damper which determined how long the plate was allowed to resonate. An example of a mechanical damper is an automobile shock absorber.

Jonathan pointed out to me that the reverb could be controlled remotely from a panel in WABC's "News Control", which was adjacent to the main studio 8A. During the late 60s they routinely turned off the echo at the end of Dan Ingram's show (5:55pm) and didn't turn it back on until Cousin Brucie began (7:20pm). The time in-between was a network and local news block. He also pointed out that sometimes they'd forget and the news would go out with echo... or Brucie would come on bone dry.

You could find smaller versions of reverb in organs and guitar amplifiers of the time, but in most small reverb units, this is accomplished only with springs because of space limitations. I believe the spring technique was a developed by the Hammond Organ Company, but I may be wrong. Now, this effect is easily achieved with digital effects boxes about in 2 or 3" high rack mount units or simply with your computer sound board. This effect is now used at WCBS-FM to recreate the old sound, but I honestly do not know what they use. I have a Lexicon LXP-15 digital effects unit myself, one effect being called plate reverb.

Jonathan told me that they later reduced the size of the mechanical units by replacing the large, heavy metal vibrating plates with gold foil.

As a side note, I made my own mechanical reverb unit by breaking open two crystal phono cartridges and removing the crystals, each with the pair of wires intact. I bent two ends of the spring so that I could glue the flat crystal units between two windings and suspended it between two hooks. I applied a low level signal to one crystal (yes crystals work in reverse) and wired the leads of the crystal at the other end to the input of an amplifier. Bingo! I had my reverb.




 

Oh my gosh I was just about to comment that these things sound like the box they used at WABC in the 60s.   One of our Big Boomer top 20 60s rock stations here, WCFL 1000 (the other being WLS) used a reverb sound in the 60s also.

What is gained by introducing a touch of reverb?  Better intelligibility?  I'm always ready to learn about audio improvement methods.

Rob

Very very interesting.  I guess ya never know these things til ya axe.


Speaking of the large metal sheet reverb -   I worked in a recording studio back in 1972 as a technician. I built audio gear for the customers based on the studio's IC designs.  In the recording studio back room hung a large sheet of galvanized sheet metal. It was about 4' X 8' suspended by springs. I remember the input and output driver and sensors mounted at opposite ends of the sheet.  This studio was high class, so I know they had the best reverb unit for the time.

Anyway, one day they were recording and I walked by the sheet with my boss. We could hear the faint sound of voices coming out of the large sheet showing they were using it. I thought I saw him tap the sheet as a joke - but I was wrong - he just bent down to listen. I then followed by and gave it a bang with my fist, thinking it wud be funny. As we walked into the studio, everyone was looking at us and very POed. We had just destroyed their mix... :o

Based on what I've read here, I'll look into digital reverbs again. I just want a wee bit of reverb that will barely get noticed. I always thought they sounded good when used in small moderation. After all, if Cousin Brucie used one...

Anyone have a good digital delay box for sale? I don't want a full blown SGT Anderson voice changer and all the stuff, just a high quality digital reverb.  As I said , the two I have, one from RS, are total crap and sound like it when used.  I used to have one that did symphony hall effects and all that, but sold it on eBay. I guess it did sound pretty good, but wasn't sure if the spring units were still the Cadillac.

T

What did you do for work in 1973?

"What did you do for work in 1973?"


heheheh - All was forgiven after a swift boot in the ass.

One thing mentioned above is intriguing about Kevin/ AIO's reverb -  Rememeber Tony Bennet singing , "I lost my heart in San Fartcisco?" If ya listen closely, you will hear tremendous reverb on the SSS's. (extreme highs)  It almost made them wispy sounding. Just like Kevin, it wud be very interesting to try using a splitter to enhance the highs only and see what it produces.  I remember my Sgt Anderson box having a freq slider to focus reverb on a particular audio band.



After all, reverb MUST enhance communications cuz you'll be talking after you've stopped talking, right?  ;D


(On my way outside to climb up to erect a dipole at 90' - cold out there. The local dipole at 60' over the house is being replaced with one out in the clear)

T

I recorded with a group at RCA Camden in the 60's.     The reverb they mixed in to the recording was from an upstairs hallway, that had a speaker at one end and a pickup mike at the other.

Another quick reverb source could be a computer.    Many of the software audio equalizers have artificial acoustics available.     I just got a Gateway netbook.     Clicking on its equalizer, there are some sound environments like small room, cave, large hall, etc. that adds the right kind of reverb and acoustics.   Since it runs up to 6 hours on battery, you could probably hook up the mike input and line output and not worry about ground loops or hum for a while.   YOu could probably use it for logging at the same time.

Andersen Labs held a bunch of patents on sheet steel delay lines used at RF. They were pretty cool devices. I think used in the radar of the patriot missile.

all the computers i've seen around here you can go and set it to add sound effects to your audio that will give the same effect as a reverb. It should make the audio sound louder. What i tried doing was letting a receiver turned on really low and allowing the audio from it to be picked up by the microphone, causing a slight amount of echo. It's not perfect but it does seem to make a difference, the trick is to keep the audio down low enough to prevent feedback, but at the same time to just make it loud enough for the microphone to pick it up.
Shelby

ummm.. I got a stack of guitar amps and keyboard with Reverb units. Maybe I will drag one in and try it.

Here ya go Tom:

http://www.tubesandmore.com/   Clack on reverb tanks.

(tom does not click he CLACKS on the air)
C

Digital reverb is by far better than the old spring units. But again cheap digital units will sound cheap and u will not have the flexibility of the more expensive types.

Bill

Ah yes, EMT plates. Virtually unobtainium these days, and priced accordingly. By the same token, virtually anything made by EMT is priced astronomically; the company largely ceased operations back in the early '90s if I recall correctly.

Reverb was somewhat popular for AM broadcast stations back in the '60s and 70's, not only for the "big-sound" effect, but because it does increase the density of the modulation to some degree, making the on-air signal sound louder.

My personal feeling on the subject, effect issues aside, is if you really want to increase the modulation density of your signal, use proven audio processing techniques such as gain compression and limiting.

73,

Bruce

Speaking of REVERB,  guess what EGC's "honers" was related  to... 

Agreed ;)

I had used a Behringer Virtualizer Pro on an oldies AM station 7 or 8 years ago. 
It has a number of presets, including an emulation of a plate reverb, similar
to the sound you'd get from one of those old EMT plates.  They go for about
$100 new.  For a hundred bucks, it didn't sound bad at all.  Plus, it was 5 feet
from the 500 watt transmitter, and....no RF problem.

Reverb is one thing, but PLEASE don't start using a reset beep!

73
Ted  W8IXY

One of the purposes for the reverb was not only an audio effect, but they thought it would increase modulation, by sustaining the audio. I have experimented with that and it is a slight amount, but to the 'bcasters that's revenue to them.
I have heard Amateurs using just a touch, and you need a really good quiet RF path and be transmitting hi-fi audio like WABC did during the 60's to notice the reverb.
I throw some reverb on my oldies show on WBCQ with the Alesis digital reverb and it has to be excessive reverb to be noticed. WBCQ cuts audio off around 5kc, and Timtron says there's still a little energy up to 7.5kc.
What's neat about the PLATE sound (the Alesis and other more expensive digital reverbs) is that it's the mids and mid-highs, escpecially sibilance, that are treated with reverb, the lower freqs are passed thru. That's why there is a mix control on the unit. The Alesis can give 9 different flavors of the Plate effect.
The Fisher reverb was the best sounding add-on for their top-o-the-line receivers.
Reverb is not throwing all audio into some springs. There's a separation of certain frequencies to get the right effect.

Fred

Ted,

I will look around for a used Berhinger reverb. I have a 6-band Berhinger processor and a 31 Band Berhinger EQ, so I do like their gear.

Fred -  How is the routing done to use reverb on only the audio highs with the Alesis or other reverbs? Does it require external splitting before the reverb or is it all done within the reverb itself?


T

I just bought this processor on eBay - new for $100 and free shipping.  Lots of reverb effects - plate cathedral, etc.   Knock yourself out.

BEHRINGER DSP2024 VIRTUALIZER PRO FX

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200412984785


I had one of these types of processors before and the weird effects get old real fast.  A touch of reverb on the highs is all I want out of it.  It doesn't include a roger beep though...  ;D


** I'm also thinking of picking up one of these "Dyno-Foggers" for the shack - for those special QSOs. (With a foot pedal for keying up with the rig)

http://cgi.ebay.com/AMERICAN-AUDIO-DJ-DYNO-FOG-II-1000-WATTS-FOGGER_W0QQitemZ190354416096QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2c5201e1e0

T

While your at it Tom, you should add the following....

http://cgi.ebay.com/RGY-RGY-DMX-laser-Show-light-stage-Equipment-Disco_W0QQitemZ280444136571QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item414bc5ec7b (http://cgi.ebay.com/RGY-RGY-DMX-laser-Show-light-stage-Equipment-Disco_W0QQitemZ280444136571QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item414bc5ec7b)

OK Tom I'll be listening to the Tom Vu show on K1JJ/WABC soon.
The freq split is done inside the box. I'll look at your booty links and see what you got........cawmawn.

And this weekend I'm making a special effort to get my arse in the shack for some whirl wide radio. Sounds like yous guys had the real fun of amateur radio with the DX on 75. I don't care if it snows 2 feet.................RADIO


OK looking at your links and you are having a mid-life crisis with the fogger and disco lights. Jack K9ACT hosts a video camera "Ustream" site that you essentially have a video conference with others in a QSO on 160M. Open up another venue on 3.885 and have whirl wide coverage!!!!!!!!!!
Phred

I have a DSP-2024 and have not been quite sure if the bypass is totally transparent.

So you got one, Dave.  Hmmm... so I might be stuck on reverb all the time?  Then get used to it.... ;D


I remember my old effects box had a 180 degree polarity (phase) shift thru it and also came on with Sgt Anderson thriller effects at random when big RF was flowing. I think Berhinger is better with RF bypassing.
It appeared NOT to have a hard switch bypass either. Maybe the 2024 will need an external  in/out switching to compensate.   

 
I shud have just bought a disco ball for the shack and been done with it.



T

It's easy with the Flex -- just have a little RF in the shack ;D  I never thought much about but I bet I could play around with the effect by changing the TX buffers once I detuned the VSWR

Tom,
This is just an observation and my personal taste...
When I hear a lot of reverb or worse case, echo, all I can think of is some good buddy CB transmitter.
With the quality of the equipment u always run.........please dont overdo it!

JMO.........Bill

1/2 price sale going on:
http://www.cheapdjgear.us/Mirror_Balls_s/3.htm?gclid=COKF0NWnnZ8CFQ975Qod3i4FTA

And you'll need these to:

(http://www.dressthatman.com/pics2/pant/pant201.jpg)

Pete,
I cant stop laughing........

Gotta get me them britches......

Bill

Here we go fellas.......YYYYYYY MCA YYYYY MCA YYYYYYYYY   MCA.

Phoggy Phred

no, ......dont use it at all, until you in with the in crowd that gets it...then go insane for 5 minutes, and put it away until the next time you want some giggles.  :D

leds, disco ball, reverb echo set to 'STUN' set it all to go off when you drop that maul. video for you tube.

Tom,

If you feel adventuresome and want to roll your own, consider the Holtek IC P/N HT8970. It is used in many of the kareoke machines sold as consumer products. I acquired several samples of the part and used one as part of a VOX circuit that needed a long audio delay. It is real easy to use and is available in a DIP package. It contains several Op-Amp stages for active filters and a combination A/D and D/A plus 20kb ram/shift regiter and built in clock oscillator. The audio is digitized and passed though digital delay to then be converted back to analog audio. The clock speed determines the delay time. You cmbine delayed audio with input audio to create echo or reverb effect. Unlike the spring type reverbs, you can control the delay, etc.
 
http://pdf1.alldatasheet.com/datasheet-pdf/view/64504/HOLTEK/HT8970.html

heheheheh ---  Ever see the show, "Cash Cab" where the contestants get into a cab, the host acts like some dummy, then suddenly pushes the button?    


Yes, the disco ball, laser lights and fog machine would be a great addition to the BIG good buddy mobiles running 4X15's.



Bob: Thanks for the info on the 8970.  The box I ordered will be here soon, so I'll take the easy way out for now.

T

Will you be calling the Reverb Net soon? That's the last time I had the spring reverb hooked up. It was always fun to bang the box and listen to the spring rattle and shake with all that reverb.

We will need Brent, The Derb and the Tron in a sacraficial ceremony to bring the Reverb Net up from the dead.

BTW, my new reverb just arrived. Gonna finger out the menu and stuff and give it an on-air try maybe tmw.

Maybe we can do some more 75 or 40M Dxing tonight.  What a blast last night! You and I were ruling that DX window for hours with an iron fist -   We had Boris', Vlads and Serges all lining up begging for action... ;D

T

I will be on the AMI net on 3870. This starts around 7 to 8 pm on 3870.  I will join you guys after the net. Or join in the net also!

C

Begging for action. And you left them hanging by signing out in the middle of a big pileup.

I'll tune around this evening. Checking into the West Coast AMI Net is usually a nonstarted because there are usually some SSBers on 3868 kHz that are located in the eastern half of the USA.

Load the thing up max.  There are SSBers on 3870 also.  Yelling, Playing music...Belching.  Worse then 11 meters.  This is why we have HI and low power.

Also.. You guys can sign into the Stickam.com site and watch the round table of AMI guys on camera.  Its normaly at www.stickam.com/wj6w or www.stickam.com/ko6nm

It should be fun.. I am going to put on my Giant AFRO Wig and Plaid Bell bottoms. ;D

Clark

The reverb arrived today. (Berhinger Virtualizer Pro)

It was fairly intuitive and I set it up with a simulated reverb spring.  I cut the unit's internal bass and enhanced the highs using the reverb's internal settings until it worked only on the highs. When I hit a bass note, there is no reverb. When I hit an "S"  or "CH"  it has a wispy sound to it. I like it!  

I found adding in about 5% to 6% reverb  to the mix was about the right subtle touch.  We'll get some reports on it tomorrow.

T

Tom, Do you run any compression. 

I added the DBX 166XL.  It is a compressor and peak limiter. It has a feature so the low end is not compressed. Only the mid and high.  I set it up for 6 to 8 DB of compression. Then used the peak limiter to knock the tops off the scope pattern. This way to save the iron and transmitter. 

Its louder.. I can turn it off and on. But I am not convinced makes me sound better.  Like your sound..

Clark

I gotta see this!

I still want one of those LED flashing callsign badges for my hat, caw mawn.


Clark:

I use the Berhinger 6-band compressor. Really like it for AM - and especially pre-programmed on ssb for its noise gate to mask blower noise.

I'm curious of your reason for not compressing the lows but doing the mids and highs?  

T

Download the DBX manual and have a read. They give you settings for various applications. It was suggested I use this feature so the low end remains unmodified.

In testing, I found that the sound was better to my ears when I did not compress the low end. I had a nice smooth low end with a louder punch.

I guess the thing I cant get past is simple.  Do I sound more HIFI with compression or without.  Maybe I need to take the Eton RXer up to the park and listen to a buddy transmit the king in both modes.

C

Clark,

I can also selectively not compress (or lightly compress) the lows with my 6-band compressor, so will give it a try to see what it sounds like. Tnx for the idea.

As far as hi-fi, I have three setting I use on the fly - one is bypassed compressor, the second is just a slight bit and third is heavy compression. There is a time and place for all three.  The uncompressed  sound is more hi-fi, cuz compression in itself is a form of distortion.  You just need to get a good audio frequency balance without the compressor set up. The compressor tends to even out the various freq levels when used.

T

You can compress the lows and highs separately and differently with a multi-band unit like you have Tom. When dbx recommends not compressing them, it amounts to an admission their box is incapable of properly dealing with lows. Not good.

You crack me up Steve.  It handles the lows fine. I like it with the lows not compressed. Lots of units do not even have this option. It also has Over easy.  But thats probably there to cover up some weakness in the box also.

C

You are easily amused.   ;D

My point is that single band compressors are limited. That's why BC stations use multi-band compression and have for decades. Tom has a six band box, so there is no need to not compress the lows or any other part of the spectrum.

Unless he likes the sound of uncompressed lows like I do :) 

Nite.

Clark

I like the sound of no compression at any freq, just like in person.

Agreed.

C

Hope to catch you on the radio over the weekend. It's time for another coast-to-coast bash! See if you can get more of your homies out that way to fire up.

Cool.. FIred up the king right now.. Its AMI night.

Yeah, let's make some coast to coast noise this weekend.   Youse guys can beat me up about my new reverb sound.  That a good incentive to get on, right?

T

I had to pull the plug. Its raining here and I saw lightning out the window.  Guess I will go read a tube manual and go to bed.

C

TOM Said:It was fairly intuitive and I set it up with a simulated reverb spring.  I cut the unit's internal bass and enhanced the highs using the reverb's internal settings until it worked only on the highs. When I hit a bass note, there is no reverb. When I hit an "S"  or "CH"  it has a wispy sound to it. I like it!

 
WOW!! Tom, I'm disappointed in you.
The Alesis reverb takes care of that sort of thing without surgery.
I'm gonna have to get into the reveb net too.......look out

Phred

Fred,

The Berhinger will do as described above with its own internal settings too. That's what I meant when I used discriminated highs as a high pass filter for reverb. No external surgery required.

The menu on this thing is quite user friendly - it uses five manual knobs to control parameters on the menu screen - unlike those cumbersome " < > " arrow keys many units use.

I think I got the "AIO" sound on the highs only - we'll see from reports.

T

Hi -

I just happen to have a spring system reverb that was in use in a commercial radio station until about 3 years ago (I'm the CE for the station), I have been looking to get $100 for it at a few hamfests, but I guess it's known to only a few what it is - does - or sounds like!  We used at the station with just a small reverb injection back into the station audio when the mike in the studio was turned on to give "presence" to the sound. It really did it's job, we replaced it with a new console that was solid state, of course, and it had a similar reverb sound unit built in.

Ever since it's been sitting in one of my closets. If interested, let me know.

Regards,
Don, W2DL

Thanks for the offer, Don.

I've already received my solid state unit and it's working FB. But maybe someone else here will be interested in your authentic model... ;D

I set mine to "spring" reverb simulation out of about five different methods in the menu.

If you get no buyer here, there seems to be a big market on e-Bay for spring reverbs.

T

spring reverb would make a good add-in for a well-tempered Ker-Chunker. If your Ker-Chunker involves motor-generator starting, then a digital reverb set for a very short delay would be interesting.

Being an old bastard....the best spring reverb I ever heard was made by Hammond. It was 2 springs that were inside of 2 tubes that were filled with some sort of oil.....I think it was mineral oil. These tubes were about 3 to 4 feet tall and installed in the vertical position in a tone cabinet that was made by Hammond.
To change the sound of the reverb one changed the viscountcy of the oil........
Anyway.....so there.........

Bill 

FYI - Antiquie Electronics Supply lists several spring reverbs
in their catalogs which are intended for Guitar Amps.  The
price range is around $20 to $30 ............ cheap enuf if one
wants to experiment.