MarkBassChat

This is very precise description of the problem with most of Eden amps. I wonder how it is possible that Eden didn't solve this problem for so many years (first Eden amps had exactly the same problem). Mark

Sound example may help - previously you mentioned noise but it appears that this is mains hum. Question about instrument being plugged in also deserves an answer. Mains hum is a common "feature" of Eden amps but it can be greatly minimized. I would call Steve and ask whether he knows what to do about it. Mark

Is it noise, or mains hum? Eden amps are known from hum. You forgot to mention what settings you use. Does the problem applies to both channels? At any settings of gain pots? At any settings of the master level control? How do you set the Enhance control? How do you set parametric equalizer? Did you read the manual (Setting the pre-amp to flat)? Is the amp properly earthed? I think that without providing such info there is no chance that someone can help you (unless you contact Eden service directly). Mark

The easiest test is to check the amp with another speaker. Please make sure that the jack on the back of the combo is mono (some Trace amps had stereo jack). Another test is to use a different bass. One more test: if the bass is active, is there a new battery in it? If the problem persists with another speaker and another bass, the amp may be oscillating - in such a case you need to give it to some tech. Mark

Most probably the quiescent current is set incorrectly. Another possible problem could be a cold solder. In any case this should be corrected by a tech. Mark

Exactly as Mart wrote; the preamp is already connected correctly. You need to connect the pickups, the volume pot and the blend pot (and this should be done as in any passive bass). Starting from the volume pot: the third tag must be connected to the ground, the others are OK. The pickups should be connected as Mart wrote. The blend pot is connected incorrectly, you have ti move one wire - take a look at the drawing above. Pots should be connected to the ground (by means of the copper shield). Mark

It seems to me that this preamp was already discissed here (a month or so ago). You can clearly see that on the left you have: +Bat - red Ground - black two others are input and output - you have to guess which one is which but there are only 2 possibilities. And the pickups, blend pot and vol pot should be connected exactly in the same way as in any passive bass. Mark

[quote name='StevieD_FenderP2009' timestamp='1326136567' post='1492808'] I know it works because I've been able to hook the pick ups straight to the pre amp but when I try wiring in the blend and volume pot, I can't get it to work. [/quote]Stevie, Usually blend and volume pots are is such cases connected exactly in the same way as in passive basses. So the pickups are connected to the blend pot, the blend pot is connected to the volume pot, the volume pot is connected to the preamp. It means that you shouldn't connect pickups straight to the preamp (unless it is a very special preamp). Of course there are other types of preamps and I don't know which type you have. A good quality photo could help. Also a meaningful subject of the topic . In the worst case you can connect the pickups as in passive bass (at least for Friday). Mark

Usually such problems are caused by other transistors shorted so I wouldn't count on that replacing this transistor will fix the amp. At least check other transistors for shorts. Mark

Have you asked here: [url="http://forums.parkerguitars.com/forum.asp?FORUM_ID=11"]http://forums.parker...asp?FORUM_ID=11[/url] ? What about this one: [url="http://www.ibanez.com/parts/2001_parts/el-bass/Pix-Bridge.htm#MR24K"]http://www.ibanez.co...ridge.htm#MR24K[/url] (search for Part# 2BB1MRP2K)? EDIT: it seems that this is not piezo saddle but I have a feeling that the one you are looking for is from Ibanez. Mark

Is it similar to this one: [url="http://www.thomann.de/gb/abm_3710g_p_single_bass_piezo_g.htm"]http://www.thomann.de/gb/abm_3710g_p_single_bass_piezo_g.htm[/url] ? Mark

I don't know whether it is hard to source and install but I think that it shouldn't be to difficult to fix the one that is already installed. Have you looked at it? It may be just a wire and not the switch. Mark

The question is whether you can rock it side by side but the IC's leads are still soldered to the pads on the board, or you can rock it and you see that the leads are not soldered to the board? You can either look at it with magnifying glass, or measure the voltages as suggested previosly. If it's not this problem, I would suggest giving the tuner to someone who can make more tests. Mark

Stevie, On the first photo there are 3 blue wires from the transformer, then there is a black bridge rectifier, a capacitor (the big one), IC2 integrated circuit and a small capacitor. The IC2 is the circuit mentioned by Thepurpleblob. If you have a multimeter, you can easily check whether the power supply voltages are OK (as listed above). Have you checked that all plugs are OK? Mark

I'm slightly sceptical about "transformer gone slightly faulty" - I haven't heard about such cases. What they mean is that maybe the power supply voltage is to low (e.g. 4.5V instead of expected 5V). But this you can check on your own. If you buy a cheap multimeter (£5), you will save £15 . If you post a photo of the PC board, I can tell you where to check it. Mark

This could be a power amp failure. But since you say that the amp works with another speaker I would look at the jack (or speakon) socket in the cabinet. Is there a parallel output (link) that you can connect to another cab? If you do it, this will verify the socket. Did you play loud when the amp was cutting out? I'm asking because this is a typical problem with power amps (not only Ashdown) not properly cooled. Over-temperature protection circuit disconnects the speaker. And this may happen when the fan is not cooling properly the heatsink in the power amp. Mark

At least we know that the power supply is working. I wouldn't give up. The chip that sends signals to the display is the main microprocessor. And microprocessors seldom fail. Usually the main problem is either power supply, or failed components in the nearest neighbourhood of the chip. I would open the tuner and check the wires between the main and the display board - possibly with magnifying glass. Have you tried contacting Korg service? Mark

No, coils in humbacker pickup are independent from each other. They are not connected in series, nor in parallel. It's the switch that causes that they can be connected in different ways. Without the switch you could use both coils as two separate coils. The diagram from Warwick is very poor because the remark that confuses you is just a mistake. They copied the remarks from the bridge pickup to the neck pickup and forgot to change "serial C+D" to "serial A+B" - it should be "serial A+B". Does it make you less confused? You've just found a mistake on their diagram - you may inform them about it. Each switch applies to one pickup only. It switches between series, single coil and parallel. Please note that the switch required in this case is a special 3-position switch - it may be called ON-ON-ON. Mark

G, this may help you: [url="http://alexplorer.net/guitar/mods/serpar.html"]http://alexplorer.net/guitar/mods/serpar.html[/url] The diagram from Warwick web site is for two pickups and I think that you wanted to ask about a single pickup (a humbacker with two coils). This is not the same. Mark

Stevie, This is a microprocessor circuit. In such cases the problem may be a complex one (like not working microprocessor), or a simple one (like non-contacting socket - missing power supply voltage). I would open it and check all plugs. If this is not the case, you may check whether the tuner can be switched to SOUND mode - by pressing CHROMATIC and DISPLAY/SOUND buttons at the same time. Then on the SOUND output there should be a reference sound. Connect an amp and listen if you get any sound. There is also a test mode in the tuner. You can enter it by pressing CHROMATIC and DISPLAY/SOUND buttons and switching the power on. There should not be anything pluged into the INPUT SELECT nor MUTE jacks on the rear of the tuner. I would also check power supply voltages (if you have a multimeter and know how to do it). For me it looks like not working microprocessor but maybe there is a simple reason for this like non-contacting plug inside the tuner. Mark

It looks like the signal has lower level than expected. Have you tried it with a different signal source? Are all cables OK? Mark

[quote name='StevieD_FenderP2009' timestamp='1323648073' post='1465497'] Would it make a difference that my bass has the copper shielding as well as a bridge earth wire? [/quote]If your bass has the copper shielding, it's exactly the same as the previous bass. If this is the case, you don't need to add any wire. Have you checked the preamp already? Mark

The correctness of your assumptions can be simply verified with a multimeter. Just connect the battery and check whether the current consumption is in a range 1-3 mA. I think that there is one more wire missing; the volume and balance pots should be grounded. There was most probably copper foil in the previous bass and it was providing grounding. If you don't have a copper foil in your bass, it may be required to add this wire. You can also connect the preamp to a jack without putting it into the bass and test it (also withut pickups - just touch the balance pot with your finger). Mark

I haven't heard anything about this preamp but it looks that you already sorted out all problems. I would try: red +battery, black ground, blue - isn't is just signal output (connected to the tip of the output jack)? Can you post a photo of the preamp? Mark

The final test is to connect each pickup separately directly to the output jack. If one of the pickups does not give output signal, it is to be replaced. I would also look carefully at the wires whether they are not shorted/broken. If you don't see anything, replace it. Mark