Questions wanted!
Hello Everyone- Well, I must admit that that coming up with a weekly tip involving harp amps has stretched my mind a little. Since most of you are fairly new to amplified harp, I don't want to bore you all with bypass caps, tube biasing, and transformer specs! So this week, I want someone to ask a question, no matter how "dumb" you think it may be. Even a very simple question that I might not think of could be very valuable to other members, so please, fire away!
Skip Simmons
Hello Jon- I think that Fritz and the other serious mike guys would be better to ask. I can tell you that the pros I know have all types of elements in their mikes, but it seems that the early Astatic crystal is preferred overall, not just for use with the Masco amps I have built for them.
Skip Simmons
Hi Skip is the super champ xd and the vibro champ xd the same amps
thanks Ron
Hello Ron,
I'm just not familiar with new, entry-level amps like the XD Champs. You could try them out at the music store. I'd also like to mention that a REAL hand-made Champ from the seventies is still around $400 or less.
Skip Simmons
G'day Skip, i just scored this B&H 285. its a 14w 6V6 amp from a movie projector, about 50 years old. its made for US power supply. i am in Australia, so need a step down transformer to run it. the tag on the amp says "110v - 0.9 amp"
would a 200w step down be plenty power for this?
apparently these things are quite difficult to work on due to the wiring being very crowded. obviously i haven't powered it up yet. the previous owner told me it was functional but volume was unsteady. he suggested it needed new tubes. does this seem a likely cause of such an issue?
Hello Dave- The 200 watt stepdown transformer is fine for this amp. It is quite likely that the tubes are fine, but it will probably need a few capacitors replaced and some good servicing. I seriously doubt that new tubes will fix your problem. Take a peek "under the hood", those B&H amps are very crowded inside. It will be a challenging project for even an experienced person.
Skip Simmons
G'day Skip,
took a bit of doing but i have identified this amp is actually from a British licence-built version of the B&H 179...somewhere between '47 and '52. that 110v power supply led me to think it was american, but apparently they kept them that way because there were no available projector lamps suited to operate at 240v.
i've taken it to Barry Young here in Tas, who knows the old stuff...though mainly he is a radio guy. "this wont be any problem" , and suggested i should aim at keeping it as original as possible. although he also suggested i could change the PT and run it from 240v, which would be nicer than lugging a step down around with it.
i'm hopeful it will make a reasonable harp amp, but who knows...an adventure anyway.
i've just been checking out what you have to say on your site about modified PAs...i'd love to get one of those out here, but i guess that hop across the pacific is probably way too $$$
cheers,
Dave
Hi, Skip, can you talk about the subject of matching wattage of speakers to amps? I recent acquired a 62' pro, it came with what looks like a Utah 15. I see that Jensen made a P15r for the tweed deluxe rated at 18 watts, they are relatively cheap compared to, say jbl150, if I hook up that 18watter to a 40 watt amp, could I melt the cone? Thanks, I see plenty of speakers out there, but different thoughts on the subject.
Hello Special20- Thanks for the question. We could spend quite a bit of time on this one!
Yes, you could certainly blow up an 18 watt speaker by running it with a 40 watt amp, but not if you kept the volume fairly low. It would certainly sound great!
The P-15R was never used in any Fender. The P-12R or P-12Q was used in the tweed Deluxe. I have heard small 5-10 watt amps driving a P-15R and they sounded fabulous, but if you crank up your Pro, you will risk blowing it. Most 62 Pros would come with a Jensen C-15N, but I have seen Oxfords as well.
Skip Simmons
Skip, I'm still kicking around the Masco amp models and seem to have more questions than answers. Can you give me your feedback on the MA-17 • MA-17N and ME-18?
Hello Jon- The MA-17 and ME-18 have different preamp tubes, but otherwise use a similar (but not identical) circuit. The MA-17N circuit is very different, with separate treble and bass controls, along with two mike channels. However, I should mention that the Mascos I build for harp use a different circuit than any stock model.
Skip Simmons
Skip: Do you have any insight into harp mic elements that would work well with Masco PA's?