Cool old tube based band pass filter
Cool old tube based band pass filter
Has anyone ever run into one of these? Its a Krohn-Hite 330BR Band-Pass Filter. Picked this up today at the state surplus warehouse, so I am thinking it just came out of some laboratory closet. Haven't tested it out yet, but it looks to be in good, clean condition and it is full of tubes. If it is working, I am thinking about trying to adjust the cutoff points, as the current ones both run a little low.
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- pluggin' in mics
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Beautiful looking piece! What are the EQ cutoff points you can choose from?
Making sounds with other sounds.
http://www.vinegarhillsound.com
http://www.linkedin.com/pub/reed-black/33/75b/a75
http://www.vinegarhillsound.com
http://www.linkedin.com/pub/reed-black/33/75b/a75
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- pluggin' in mics
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And then plug that shit in and tell us how it sounds!
Making sounds with other sounds.
http://www.vinegarhillsound.com
http://www.linkedin.com/pub/reed-black/33/75b/a75
http://www.vinegarhillsound.com
http://www.linkedin.com/pub/reed-black/33/75b/a75
Well, looks like there is not much inside besides a bunch of cans of spam and some weird old glass bottles from overseas. Does anyone know what the spam cans are? There are about 15 tubes in all, eight of which are 12ax7's two are 12au7's, one is a 12 ay7 and the other three are odd sized ones (in the front around the xfmr). The 12 series ones are almost all Telefunkens and the rest are RCA's. The 12's look pretty clear without any signs of blackening or wear. The big ones have some darkening at the top. Haven't powered it up yet though.
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Spam are paper/oil caps. They will be fine. These use an electrolytic cap after a cathode follower for output, so it may have large DC leakage on the output. Measure it before you connect to something else. I'm not sure you can move the range easily. These are a 4 section tuned circuit. Very cool for active eq sweeps in a mix, if pots are clean. Range switches: don't switch them with speakers up, many times these send a huge thump. If you paid $20, you paid 10-20x under market.
Doug Williams
ElectroMagnetic Radiation Recorders
Tape Op issue 73
ElectroMagnetic Radiation Recorders
Tape Op issue 73
Sounds like the "spam cans" are almost as toxic as actual spam. I once got paid to do spam sculture at a public event. I surprised at how it burned my hands.
Still havent passed audio through it yet. Will do it this weekend. Good idea to meter it though, before connecting it to valuable gear. So is the consensus that the paper-oil caps are still ok in a 40-50 year old unit?
Still havent passed audio through it yet. Will do it this weekend. Good idea to meter it though, before connecting it to valuable gear. So is the consensus that the paper-oil caps are still ok in a 40-50 year old unit?
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