| Author | Message | ||
     John Lynch |
On a 112-RP-65, the volume can be all the way to 10 and no sound will come out until the treble, middle, and bass pots are turned up. Even then you have to use the gain pot to adjust the volume up. Is this normal operation. Thanks. | ||
| carl from aus |
is this normal - im prettty sure it is because no signal can get through. still weird though anyhow. | ||
| Lynch1j2 |
Thanks. I thougt maybe there was a loose wire or something. | ||
| jj maslen |
dear steve hd 130 212 and rd 100 210 despite having read all the fab advice on the speaker imp. etc. pages i would be pleased for a simple answer on the following: - 1. the rd 100 210 specifies speaker switch set to 8ohms and specifes switch to 4ohms when using ext. cab..but seems to suggest 8ohm ext. cab preferable. 2. the hd 130 212 speaker switch is set at 4ohms questions: 1. if i use rd 100 210 as sole power amp, what speaker setting should i use for hd 130 212 cab as extension? 2. if i use hd 130 212 as sole power amp, what speaker setting should i use for rd 100 210 cab as extension? Thanks for your patience jj maslen | ||
| Steve Kennedy |
It sounds like you might have something backwards with the information on your 210. Where does it say this information (manual, back panel, etc.)? Most Music Man "twin" combos utilize 2 8-ohm loudspeakers in parallel for a total impedance of 4 ohms. When running the combo by itself it is normally run in the 4 ohm position. Unlike the other combos, the "twin" speaker combos and heads normally have their external speaker jack wired in series with the internal speakers. So if you add an external two-speaker cabinet (4 ohms) it is connected in series with the internal 4 ohm load for a total of 8-ohms, so you would run the impedance switch in the 8-ohm position. Even if you run an 8-ohm external cabinet for a total of 12-ohms, you still have the switch in the 8-ohm position. Most tube amps can tolerate up to 100% impedance mismatch in the positive direction without a problem. Check your rear panel nomenclature in the area of the external speaker jack for any wording that would indicate that the external speaker jack is wired in series with the internal speakers. Next, verify that the total internal load is 4 ohms (with an ohmmeter). The problem here is that there are different wiring methods for different models and not all MM amps still have their original speakers so you might not have a factory standard setup. |