The AM Forum

There is a post on the ebay topics that shows a BL-40. I have a BL-40 that I use with my 4x1 but my BL-40 looks a lot different than the one on ebay. Does anyone know which one is newer or what the difference is?
In my pic....the bl-40 is the unit in the middle with the 3 meters and the silver face.

You have some nice looking rack gear, especially the mod. monitor, which has become unobtainium or when one shows up is unaffordable.  I posted the eBay thing and had no idea there were two BL40s at the time, but tonight Don K4KYV told me his was the silver face type which I guess is the same as yours.  It is weird that the manufacturer would make two very different units but give them the same model number. 

73

Rob
K5UJ

Hi Rob,

It appears that the unit on e-Bay is the sad victim of the recording industry version of Hammy Hambone.

Whomever poorly modified that unit with the XLR connectors should be shot, among the other "improvements" that were made.

73,

Bruce

Just Technically,

I found a BL-40 at a swap a few years ago,  it was only about $15,  but it had the stench of a toasted power XFMR,  still was happy to find it.

All I know is what I read,  ...  but ...

http://www.uaudio.com/webzine/2005/august/index4.html

Scroll down a bit and it gives a few tidbits on on the 1176, LA-X and BL-40.

I do not know what the story is on the feebay listing.  The XLR installation IS truly gifted !   If it looks like that on the outside,  just think how it looks inside.  Pretty face,   tho.

This is a Universal Audio (UREi) BL-40 Modulimiter that has been completely refurbished and highly modified for use in a modern recording studio. There is only one other BL-40 in existence that has these mods and it belongs to Chris Lord-Alge... the reality is that the BL-40 was designed as a broadcast limiter and has some limitations when used in a recording studio situation. For example, on a stock unit there is very limited control over the amount of RMS (electro-optical) limiting that can be applied to the signal. There is no way to apply only Peak (FET) limiting in a stock unit. Also, the threshold of peak limiting can be varied over a very limited range, and the attack and release times are a fixed value. The mods on this unit fix these issues. The RMS control allows you full control over the amount of limiting provided by the LA-3A section. The Peak Limiting control gives you much more control over the amount of limiting provided by the Peak Limiting section. A switch has been added to allow the RMS meter to show either RMS Gain Reduction or Output Level. A +4/+8 dbm switch has also been added.
...The terminal strip connections have been replaced with XLR connectors. Even the prongs on the AC cord where cleaned!

- The "phase optimizer" board was removed. The purpose of this board is to flip the polarity of the signal based on the number of positive peaks in the signal at at any point in time. While that may be desirable in an AM radio broadcast application it's the *last* thing you want in a recording studio. Can you imagine the polarity of your lead vocals changing arbitrarily without you knowing it?

- The unit was then aligned using the procedures listed in user's manual, a clean copy of which is provided as a part of this auction.

- All signal path wiring was replaced with Mogami and Canare full-braid shield, oxygen-free copper  ;D cable. This was done because over time, wiring becomes oxidized, increasing both resistance and cross-talk, which affects the clarity of the sound. The Canare and Mogami cables sound great and are easy to work with.



Even if it had been left in stock condx, I think I would still like mine better.  Mine has three meters: RMS limiting, peak limiting and output level.  The controls are all hidden behind a cover that screws onto the front panel, to keep inquisitive hamboney fingers away.

I couldn't imagine paying money for that P.O.S., "tessitura" and all.

Thanks for the posts guys. Mine also has the removable door that covers the controls but I took it off for the picture........its now back on!
BTW........I love the unit, it works well.

Thanks again,
Bill

Yeah in the eBay one, I saw some sticker on the back panel in one of the photos that said something like "Modified by <someone>" and I thought, "Uh oh."  :P

- All signal path wiring was replaced with Mogami and Canare full-braid shield, oxygen-free copper cable. This was done because over time, wiring becomes oxidized, increasing both resistance and cross-talk, which affects the clarity of the sound.

What a crock!  It is the oxygen that makes up about 20% of the air that causes oxidation of the cable.  It could be pure lab grade copper with no detectable impurities, and oxidation would still occur unless it were sealed in a vacuum or maintained in a dry nitrogen atmosphere.  There is no such thing as a special grade of copper that  doesn't oxidise when it contacts the air.