Hammond H 100 series

[flguym1]

My Speaker is sounding over loaded when the bass is played or the volume is to high.. Is it the speaker going bad? No Mods have been done to this Organ
Thanks

[indianajo]

Unless the speaker surround is showing visible tears, more likely the power amp is clipping due to sagging power supply voltage. Replacing electrolytic caps C702a and C702b gives one the biggest improvement for the least money, but I replaced 71 e-caps on my H182 for great sound and full performing features. If your organ has over 10000 hours you can also have tired 5AR4 rectifier tubes. I have a "professionally maintained" H182 from a church where the hit-and-run technician replaced the rectifier tubes with inferior 5Y4's and a couple of the 6BQ5 treble power amp tubes. I believe he should have replaced C702a and C702b instead, which takes a lot longer.
The best schematic diagram is on keyboardpartner.de, although there is a full service manual rather fuzzy on archive.org. You can read the date on the original cans, usually 66ww for some week of 1966 or like that. If your caps are showing 1992 Manuf date or later or are made by FP or an oriental manufacturer, then these caps might have been replaced already. Then the next ones to do are C703, followed by the sections of the one on the power amp itself.
Read this thread about my take on changing e-caps in tube amps the cheapest and longest lasting way. http://www.diyaudio.com/forums/tubes...ube-amp-3.html FP can caps come from tubesandmore.com or triodeelectronics.com, but have undefined life. Radial lead caps have to be installed on terminal strips from those, but the caps come from newark.com or mouser.com in the US. You can get radial lead caps in life ratings of up to 10000 hours.
You wouldn't believe how striking the sound can be from an H100 if you do 71 e-caps. an A100 doesn't begin to sound like one of these, although torea said his H100 sounded something like an A100 after replacing only these two cap sections.

[flguym1]

Thanks, I guess I need to find someone who can repair it! I am still new at this, and do not want to ruin the boards.. Anyone know of a Hammond Tech in NY Hudson Valley? I searched and found not many close?

[indianajo]

Actually if you unplug the power supply chassis (high keys end in the bottom), take the 4 screws out of the bottom holding it to the wood, and take it to a guitar amp repair shop they should be able to re-e-cap it economically. That saves you the cost of a tech driving around and carrying liability insurance. You have to squeeze the latch things on the plugs to get them off. There are 10 electrolytic cap sections in that chassis that need replaced, including the ones for the string bass feature (which is a lot of fun when it works, sounds great!). You could also box it up with a lot of worms, and mail it to tonewheel-general.com in KC or bentonelectronics.com in Pasadena TX. After talking to them, of course.
Have them replace the power cord from the back of the amphenol plug out while they are at it, the rubber insulation tends to fall off under the power transformer. They can ground the 3rd wire of a new power cord to the chassis. Have them replace 10k resistors R702 and R703 while they are at it, they are mounted on the bottom of the e-cap C703 and have to come off anyway. All mine have looked burnt and read 11k ohms instead of 10k ohms, which cuts your output power. I used 2 watt resistors instead of 1/2 watt, to stop the burning.
The chassis is all point to point wiring, a good thing to learn to solder on. I don't mess with the boards (PWB's) because I might lift the traces off the boards. Also the boards in the H100 are too hard to get out (on the back of the keyboard chassis). I just cut the leads off the old e-caps up there and hook the wires of the new ones around the old leads. But whatever, guitar amp techs mess with tube amps all the time, and they are everywhere. Look for a Peavey or Marshall amp dealer on the internet yellow pages, and ask for the repair department. People who sell old guitar amps on craigslist are also often competent, but their business practices are up to you to evaluate.

[flguym1]

Thanks that sounds better

[paulj0557]

You will be very pleasantly surprised when you get your H-100 together. It really does have a very good on board amp and speaker arrangement that makes the A-100 seem weak in comparison. I always thought the A-100 could have had a little more punch. The H-100 was Hammond's successor to the A-100, think about it, Hammond did lots of R&D. You typically don't add on features and expand voicing on an organ you are compromising. The H-100 is a sleeper if there ever was one.

[flguym1]

I could not agree even more. This H series is not what I was expecting!!!! I feel as time goes on these organs will increase in popularity, just a personal opinion. Just because its a clumsy console means nothing.. Great sounding organ!!!!