Recent Posts

Pages: [1] 2 3 ... 10
1
The Wurlitzer Electric Piano / Re: Intermittent Speaker Distortion
« Last post by OZDOC on November 17, 2019, 10:54:56 PM »

Both speakers see the same mono output from the amp - so that suggests the problem is associated with the speaker - or the wiring to the speaker.
Have you checked and reflowed the solder joints to this speaker?
Have you gently jiggled the wires to see if something is not firmly connected?
Can you easily remove the speaker to see that the cone is not damaged?
And that there is no dirt trapped against the cone.

It is also possible that the distortion relates to either the cone sagging on its suspension so that the voice coil drags in the gap, or the frame of the speaker being slightly distorted by uneven tightening of the four screws, which also can cause the voice coil to drag on the gap. Opening and closing the lid of the unit while you work on it may be producing the variability you're observing. It's possible that distortion of the frame can be fixed by loosening off the speaker and carefully re-tightening it. If it's sag from aging, you may get temporary relief by rotating the speaker 180 degrees when you replace it.
2
The Wurlitzer Electric Piano / Intermittent Speaker Distortion
« Last post by WurlieNewbie on November 17, 2019, 06:21:16 PM »
Hey guys.  I have a 200 I'm bringing back to life and I've hit another snag.  The right speaker has been distorting intermitteningly.  Problem doesn't exist through the headphones or when plugged into an external amp so its most likely a bad speaker right?  But why is it on/off? Some days the distortion is completely gone only to come back again.  I haven't moved it or changed anything so I can't figure out why it's acting up.  Do blown speakers behave that way?  I'd hate to replace the speaker if it's not broken.

If I had another pair of externals I'd test it but I don't.  Question: can I desolder the two speakers and swap them to test?  Any other tests I could do before I just pull the plug and replace?

Thanks!
3
The Wurlitzer Electric Piano / Re: 145/720 Tube Amp - Dubious Power Transformer?
« Last post by dottyp123 on November 17, 2019, 03:48:33 PM »
Thanks! I will get the rest of the circuit checked out.
4
The Wurlitzer Electric Piano / Re: Stuck Hammer
« Last post by pianotuner steveo on November 17, 2019, 02:08:39 PM »
Awesome!
5
I did have one power transformer go bad, but it opened up, not shorted. It's possible yours failed due to old age, but it's too risky to just replace that part and hope for the best. You may need a pro amp tech troubleshoot it before you start buying parts.
6
The Wurlitzer Electric Piano / 145/720 Tube Amp - Dubious Power Transformer?
« Last post by dottyp123 on November 16, 2019, 08:38:27 PM »
My first post - I've been very grateful for all the information I've found so far, but I couldn't find this exact question answered previously. I hope someone might have a suggestion:

My 720A made sound when I bought it, but since taking possession I haven't turned it on. Looking at the 145/720 power amp it looks as though the power transformer has been overheated. There are big blobs of black foam that have oozed out. I took the tubes out and measured 700V on the secondary with no load - so it is not dead. I don't see anywhere else that looks obviously cooked - but I could be missing something.

Has anyone seen this problem before?  Is there a fix for the root cause?

I was planning to replace capacitors & see how it sounds - maybe I should get a new transformer from VV?

Any tips?

Thanks a lot!
7
The Wurlitzer Electric Piano / Re: Dating a Wurlitzer
« Last post by jam88 on November 16, 2019, 10:33:19 AM »
Threads on this topic:

http://ep-forum.com/smf/index.php?topic=9303.msg50803#msg50803

http://ep-forum.com/smf/index.php?topic=9359.0
  ...With the 120 and 700, the most consistent dating I've found is a piece of handwritten masking tape hidden on the back of the reed bar.  There may be other stamps on the wood or electronics (esp speakers) in certain cases...

Hi Guys, can you help?

I’m trying to date my Model 120, and approximate the serial number.  I’ve owned my 120 for 52 years. Many years ago, the serial number plate went AWOL.

There are some numbers stamped here and there. (See pictures)—

Key #1 has a faint stamp that appears to be “2  560  20”, but could be “2  569  20”—Thoughts?

Key #3 is stamped “[C]OMPO”, anybody know what this means?

Key #57 has a stamp on the underside. Using some imagination, it LOOKS like a 1960 date stamp. The stamp style is like the date stamp in the attached 112 picture. Thoughts?

(Key #4 has a Pratt-Read [not Wurlitzer] patent number; this number also stamped on the action rail. The patent was issued Dec 30, 1958, so I guess the action was shipped from Pratt-Read no earlier than January 1959.)

Ink stamp on back of the speaker “600141”—does that mean anything?



Here’s what I DO know about my piano: it is a ‘later’ 120, that had the...
  --Painted lid, not textured film
  --Simple (not the ornate) Wurlitzer decal
  --Incandescent (not neon) lamp
  --Two-hole (not four-hole) nameplate--Does anybody know the highest serial number that used the four-hole plate, or the lowest S/N with the two-hole plate?
  --Amplifier S/N 18628. I seem to remember that the amp serial number about 2000 higher or lower than the S/N on the piano’s nameplate. Do any of you know this spread on YOUR 120’s or 700’s?
8
The Wurlitzer Electric Piano / Re: Stuck Hammer
« Last post by marcmarc on November 16, 2019, 05:48:38 AM »
@Steveo
Quote
You may be able to loosen the reed bar half that is causing this and slightly bump the reed bar away from the hammer that is sticking, but the issue may come back once you tighten the reed bar screws.
And you're right! I've loosened the reed bar and not even bumped it. After i've tightened it back the hammer doesn't get stuck anymore.
Thanks
9
I’ve heard about this before, tricky one but we can vouch for Tom as I’m sure it’s related to the eighty eight key range of his suitcase.
10
Preamps, Modifications & Upgrades / Re: DIY Peterson preamp (tremolo) pedal
« Last post by 4kinga on November 15, 2019, 12:29:52 PM »
Nice!
Count me in!
Pages: [1] 2 3 ... 10