Got an H-133 with low volume...but auto-vari input is loud!

[funking honKEY]

Hey everyone, I just recapped the PS and did the cap on the motor (per Indy's advice to others). When I got her there was someone else interested in just the auto-vari, so the owner sold the auto-vari and gave me the organ. Played low before PS recap so I did that, better but still low. Then I decided to plug my small keyboard in with the 1/4" jack from the auto-vari, it was loud! Never heard my organ that loud. So why aren't the manuals as loud? She sure is capable of shaking my house through another keyboard though. Thanks for any advice, I'm a newbie to this stuff can't believe the generosity of everyone on this site.

[jbswisher]

The H series are LOUD aren't they? Really it could be a number of things with these but...I had the low volume issue on my H112. Unplugging the reverb RCA jacks gave me some volume back (I am currently working getting reverb back). Then I found the "mystery circuit board" behind the Main/Echo switches along the side of the organ inside the switch assembly(you might or might not have this board). I unplugged the wires connected to this. Taped them each off and I got full volume back! I can not say FULL volume yet because I am onto replacing the caps as you did. Other members here suggested this, so I tried it. Here is a link to one post that talks about it.http://www.organforum.com/forums/sho...or-my-new-H112 Have you cleaned all you switches yet? There are a few pots on the circuit boards behind the switch assembly that could use a good cleaning. Did you clean your drawbars by any chance? This cleaned up my H pretty well. I'm sure Bobmann will be along to help soon.

JB

[indianajo]

I don't have the Mystery board in the top on any of my early serial number H100's. Changing C702 and C703 on the power supply doubled my volume. Changing C401, C306, C356, C366, C330, C332, C303 and C307 on the power amp chassis doubled the volume again and added a lot of bass. Changing C324 on the percussion/pedal chassis doubled the volume again and made the percussion start working. The electrolytic caps changed up on the keyboard chassis back brightened up the sound and added bass. I did have to clean a potentiometer on one of the keyboard chassis amps, and the dealer tech had soldered a couple of wirewrap connections (the black coax center ones).
With radial lead caps costing $1-3 and freight from mouser or newark being $7 I don't see the point of buying 2 or 3 caps at a time. I do see the point of changing a few at a time. I made a few mistakes and testing after every couple of caps helped focus my eyes on the problem area rapidly.
I sprayed out my drawbars with Freon TF cleaner but did not disassemble them. Didn't notice much change. All the positions of all harmonics work, but they scratch a bit if I move them while a key is down. I play 2 handed so I won't be doing that. Bob thinks it is very important, but maybe there was a production change adding more grease before his late units were built. I don't think drawbar disassembly is worth doing on my units.

[funking honKEY]

Hey guys, thanks for responding! I cleaned all I could without disassembly. I should do that soon. As for a mystery board I don't know. There is a board on the left wall looking at it from the back. Has a few transistors and and two coil looking things with slim sidewheel trimpots. Maybe my problem is in the preamp, because the keyboard I have hooked in is loud even with that keyboard volume low. Vacation next week and I hope to get her back in shape.

[indianajo]

As for a mystery board I don't know. There is a board on the left wall looking at it from the back. Has a few transistors and and two coil looking things with slim sidewheel trimpots.

The board on the wall on the high keys end is the brush/cymbal generator. Mine worked without new capacitors or cleaning. whoopie, lower case 6 point font.
The mystery board that kills volume is in the tab chassis towards the high keys end, I believe. I'm just going on what torea said. To get the tab chassis off, you unplug the light, take the screws out of the back bottom of the top, and remove the wood top. Then remove the 6 preamp covers, then remove the screws in the top of the tab box. Then get a big (1/2") screwdriver or a small crowbar, and put it in the slots of the front of the cover, and pry back by twisting the blade. The cover is held in pretty tight with steel clips. Took me a day or to to figure out the slide back part.
With that cover off, that is how I got the tube of the contact cleaner can in the sides of the tab switches and the drawbars and sprayed them out. Warning, aliphatic hydrocarbon contact cleaners are very flammable, no smoking, open flame, pilot lights or electricity turned on or off within 10 m. Set up a fan before spraying. Brominated and florinated hydrocarbon contact cleaners are very expensive and dissolve PVC plastic, which is what H100 parts are made of. So don't use those.

[funking honKEY]

Playing more last night with my son. Toggled main/echo tabs seemed to make some change in harmonics..? Also louder without vib . Boy do I love this instrument! The bass end is deep (not the pedals), so left hand bass is my goal. Thanks guys for the good direction, I'll get into it this weekend/next week.

[indianajo]

The electronics are tuned flat with all the e-capacitors at the nominal value. At 40 years they sound like a kazoo, with mid range only, not much bass or treble. As you noticed, just changing the 2 caps in the power supply will give you some bass. 69 caps to go. (I didn't do the harp sustain ones, there are 110 of them at $6 each.). There are 6 or more paths through the various preamps and vibrato drivers and stuff, different circuits will have different frequency response until the caps are back to nominal value.
I love the bass on my H182 #9574. With one 15" speaker and 30W bass amp, it has more bass than my dual Peavey SP2XT hifi speakers with a 15" woofer in each one and a 60W/ch amp. SP2XT's are 3db down from flat at 53 hz. That is on organ LP's, I think the LP engineers used to cut the bass back to keep the needle from rattling in the groove. I have one 1953 Colombia LP where the bass is pretty prominent.
Besides trying to copy E. Power Biggs at the Flentrop organ on Passacaglia & Fugue in C min, I'm inspired by the bass to learn the bass lines on pedals to "Inna Godda Divida", "They Call me the Breeze", and some embarrassing Joan Jett song I'll never sing but has a great bass line.

[funking honKEY]

Unfortunately my #6842 (I think) didn't come with a bench. Typical so I've heard. I've never heard the bass pedals although I do have them. I need to build a bench for that. Must be awesome.

[mdainsd]

My H-182 had the mystery board and it was the cause of low volume on mine. You need to get to it and you will probably be very happy.