Author Archives: randymorgan1

Organ Repair

We perform service calls on all brands of organs, keyboards & digital pianos.

Organs in most cases to express it simply are an electronic keyboard in a nice full size case with typically one to three keyboard manuals and a foot base section. – by far the most common problem we run into with them are contact issues and in the older units in particular failed and or out of tolerance capacitors.

Whatever symptom you may be experiencing with an organ or electronic keyboard, we would be more than happy to come out and have a look at it for you.

While we do work on Hammonds we do not work on the pre 1975 tone wheel organs – those are a whole different animal as they are electro mechanical rather than electronic and we simply do not have the parts resources to service them. For a list of common Hammond model numbers and types please follow this link  https://en.wikipedia.org/wiki/List_of_Hammond_organs

Please note we do not buy sell or accept free organs – Craigslist is your best bet for that sort of thing.

Jukebox repair and service

JukeboxI offer on-location service in your home, game room, or place of business, on practically all makes, models, and styles of antique jukeboxes, modern day CD replicas, and commercial units.. From the old 78 RPM’s, to 45’s, and the current CD players…Names like Wurlitzer, Seeburg, RockOla, Rowe AMI, NSM, and others. Experienced in working on all kinds of electronics in my over 35 years of being an electronic repair technician – repair of selector mechanisms, carriage and transfer mechanisms, and amplifiers, from tube-type to transistor, as well as integrated circuitry.

Note: Jukeboxes are a service call only item due to their size and sensitivity to being moved around.

Mam … Step away from the super glue.

I just spent and extra 30 minutes time carefully extricating a jack from a circuit board so as not to damage the board because someone attempted to glue the plastic jack back together.

If something breaks on your gear super glue may sound like a good idea at the time, but 99.9% of the time it is not.

Super glue

Most of the time it just makes things 10 times worse than they already were.

It is so useless in electronic repair I don’t use even a small tube of it in two years’ time.

Do yourself a big favor and think at least twice before you try to super glue something.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Roland Juno 106 voice IC’S

Juno 106

Roland stopped making the replacement Ics some years ago. However there is a guy over in Europe who is making a good quality reproduction. So if you have an old juno laying around that you thought was beyond hope due to bad voice IC’s you thought wrong.

I have installed this new part in several Juno keyboards to date, they work great and even after several years i have yet to have had one fail.

Here is a link to the part: http://www.analoguerenaissance.com/D80017A/

I do not recommend attempting this one yourself as the traces on those old boards are pretty touchy and they can be destroyed pretty easily.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

 

What you should know about Tube Testers

Tube tester 4 (002)

I would like to talk a little bit about tube testers and explain why we do not use one here at the shop due to their unreliability and limited usefulness in trouble shooting tube equipment problems.

The absolute best test for a tube is testing it in the actual piece of equipment the tube will be used.

The field service tube tester was developed for the telephone, radio-TV, communications and industrial electronics industries to provide basic tube testing capabilities to help technicians and engineers locate defective tubes. The early testers only tested cathode emission. They worked fine in the early days of the industry before the circuits and tubes became more sophisticated.

Over the years there were many approaches to tube tester design. The features, accuracy, and the tests available differ widely by make and model. Some manufacturers wanted to focus on simple low cost units to find weak or just bad tubes. In all cases tube testers were at best a set of balances and trade-offs in the evaluation of the tubes vs. the cost of the tester.

Even the best service testers made trade-offs in design to allow for simplicity of use, the ability to test many different types of tubes, features, and accuracy, balanced by the price of the tester. The service tester was a piece of test equipment to be used by professional engineers and electronic technicians to aid in the process of repairing tube electronic equipment.

Testers were designed with the understanding that those using them were knowledgeable in tube operation, the equipment the tube was used in, and how the tester worked in evaluating tubes. This is more often not the case today when someone acquires a tube tester and attempts to use it.

There are many types of tube testers and most of them date from the early 1950s to late 1960s. The usefulness of each make and model will vary with the type of equipment you are servicing. Considering the fact that these testers are vintage, the age, actual usage, and condition of the tester will have a big impact of how useful it is in testing tubes today. Over the years, moisture, dust, and dirt can be absorbed by tube sockets, switch wafers, and wiring causing many leakage paths that would contribute to false readings. Calibration of the tester is another factor that will affect accuracy and usefulness of the tester. Many simple testers do not have any provisions to make internal calibration adjustments.

Tube testers fall into two main categories- emission testers and mutual conductance testers. Other types of testers would include laboratory and special purpose testers.

Emission testers are the most common testers. Popular brand names include Heathkit, B&K, and Sencore. There are a few problems using any emission tester. The emission test basically connects all of the elements of the tube together, except the cathode, and tests it as a diode for cathode emission. The meter scale is most commonly labeled “Bad-?-Good”. Most tubes depend on the control of the electron flow rather than the amount of electron flow. This important shortcoming means that emission testers will miss the output tube with a cathode ‘hot spot’ which is hidden when the grid is tied to the plate. When a cathode has a ‘hot spot’ most of the emission current stems from this restricted area on the cathode. A control grid does not have the current control action under this condition and when the tube is placed in an amplifier, it draws excessive current and goes into thermal runaway.

Cheaper emission testers used a low current power supply. A tube tested on a tester with a low current power supply may have enough emission to yield a “Good” reading on the meter, but when the tube is placed in an amplifier that is drawing 150ma to 200ma, the tube may not be able to provide sufficient current for operating at peak efficiency.

Emission testers frequently operate at low voltages, with some testers as low as 30 volts. These testers only provide a static test of the tube that does not represent the conditions the tube will be subject to in an actual circuit in which it would be used.

Some emission testers apply too much current to small signal tubes and when the emission test button is held down on the tester for an extended period of time, the cathode is stripped rendering the tube useless. Another shortcoming of many emission testers is the leakage test. In testers where all of the elements are connected together all of the leakage paths are in measured in parallel, which could cause perfectly functioning tube to fail the leakage test. Some testers were advertised as having the most sensitive leakage test in the industry. This many times was more stringent than circuit application requirements and again causing many functional tubes to fail testing.

Most mutual conductance testers work by applying an AC voltage to the control grid of the tube, while maintaining DC voltages on the plate and screen grid. Most of these testers use the 60Hz line frequency transformer coupled as the input test signal. The cathode can be biased with a small positive DC voltage, or the control grid can have a small negative DC voltage. This setup actually dynamically measures the AC gain of the tube, rather than the actual transconductance.

A variation of this type of tester is the “grid shift” approach. This uses a DC voltage on the control grid that is shifted and the change in plate current is measured. Tube theory says that transconductance is the ratio of change in grid potential to the change in plate current.

Many believe the AC (dynamic) method is superior because it reflects true RMS values, regardless of waveform distortion. If the line voltage is not a true sine wave, which is common in heavy industrialized areas, the dynamic tester will still indicate correct values. Hickok held the patents for and made most of the mutual conductance testers.

Many low priced “conductance” testers used AC voltage on all of the elements can actually damage high transconductance tubes. The heavy rectification current caused by driving the control grid positive can overheat the grid wires, resulting in critical spacing to be upset. The tube then actually loses transconductance.

There are special purpose tube testers that are usually special test fixtures that are used to test a specific tube for a specific purpose. These special test fixtures are usually not available commercially and are usually built by the manufacturer or individual who intends to use them. These are usually found on assembly lines for grading tubes to be used in a certain application.

As was stated at the beginning of this article, the best test for a tube is to test it in the equipment in which it will be used. If you intend to acquire a tube tester, be aware of its limitations and realize that some good tubes will test bad and some bad tubes will test good under certain conditions.

Speaker phasing

This is a simple, but important topic.

Speaker

All speakers as most of you know have a positive and a negative terminal. If these terminals are hooked up backwards the speaker will still work, and if only one speaker is used you will probably not even notice the speaker is out of phase.

The problem comes into play when using more than one speaker cabinet, or multiple speakers within one cabinet.

If one of the two speakers is hooked up backwards then the two speakers will be out of phase and when played together they will sound very thin as they are essentially cancelling each other out. This is because one cone is moving out while at the same instant the other is moving in.

In cabinets with multiple speakers it is also important if you have to replace a speaker that you match it up as closely as possible to the original, or replace both at the same time. The reason is if the two speakers have different efficiencies and cone materials then the cones will move at different rates which creates another type of phasing issue.

When hooking speakers up you cannot always rely on the markings on the speakers. I have seen many speakers over the years that the positive & negative leads were labeled backwards.

The good news is that it is extremely easy to check for phasing issues and proper speaker polarity, all it takes is a 9 volt battery.

With nothing else hooked up to the speaker touch the positive lead of the battery to the positive lead of the speaker, and touch the negative lead of the battery to the negative lead of speaker. As you are looking straight into the front of the speaker it should move towards you.

The motion when the speaker pops when you hook up the battery is what you are looking for. . Do not leave the battery hooked up for more than a few seconds at a time.

When doing this with a cabinet you can simply use the input terminals of the cabinet to perform this test.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

 

Cleaning controls or “pots”

Controls

Almost every piece of equipment be it a keyboard, a mixing board, a guitar amplifier, or an effect unit has some good old fashioned potentiometers (Pots) that at some time in its life will need to be cleaned.

Cleaning controls is a pretty simple process; it is the getting to the controls to clean them that can sometimes be complicated.

Fist a warning about faders or slide controls. Do not clean them unless the absolutely need it, and only use special fader only cleaner, and finish up with some fader lube. If you use anything else the controls will become so stiff you will barely be able to operate them. Even when you use the proper products on them they will still be stiffer than they were before they were cleaned. That is why I advise not cleaning them unless it is necessary.

Fader controls unlike rotary controls can be cleaned without taking the equipment apart. You just spray the fader cleaner in the slot that shaft rides in that the knob it attached to. Then work it back and forth over its entire sweep several times, apply some fader lube in the same way, and you are done.

Cleaning rotary controls requires disassembly of the unit being worked on. Once you have accesses to the controls the process is pretty simple. Most, but not all rotary controls have a slot or other opening on the back, or side that you can spray your preferred brand of control cleaner into.

Clean the controls one at a time, do not spray them all first and then go back and rotate them as it is not nearly as effective as spraying the cleaner into the control and then immediately rotating it vigorously several times over its entire sweep.

Here at the shop we generally clean each control twice, the reason we do this is if you have to spend several ours on cleaning the controls on say a mixing board that you had to pull all the circuit boards on to get to the controls you sure as heck don’t want to have to pull it all back apart because you were not thorough in your first attempt.

A few additional notes on control cleaning.

When cleaning controls on keyboards, and synthesizers be careful not to get any control cleaner in the area of the keyboard display, or the keyboard contacts.

When cleaning controls on guitar amplifiers try not to get any cleaner on the tubes or any of the power resistors.

When cleaning controls on mixing boards there will generally be a lot of cleaner run off after cleaning the controls. Put the board on some old newspapers or something else absorbent and let the cleaner drain off before you put the cover back on it. It generally helps to do this with the mixing board left sitting in a variety of positions to facilitate draining of the excess cleaner out of the mixing board controls.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Buyer Beware!

The internet is like the old Wild West, pretty much out of control in many respects.

If you are buying something new on the internet please check to see that who you are buying it from is an actual authorized dealer for the product. If they are not there are two possible problems.

One of them being is the product could actually be counterfeit. Yes it is true counterfeiting is not just limited to Gucci handbags any more.

The other is they are second sourcing the product which makes them the original purchaser and you are considered as far as the manufacturer is concerned to be buying it 2nd hand from the internet seller.

In either of these cases the manufacturer will not honor the warranty on the product. In the case of counterfeit products many times the manufacture will require a serial number to order repair parts and if the serial number is not in their system the will not sell the parts to repair it.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Broken USB ports

usb port

Many pieces of gear these days have USB ports of this style.

Keyboards use them, DJ mixers Use them, DJ control surfaces use them, some standard mixing boards use them, some effects use them, Digital recorders use them … On and on the list goes.

The problem is the connectors were really designed to be plugged in and left alone.The music industry really needs to come up with better connector to use. The big problem is about 25% of the time when these break off the circuit board they also damage that circuit board.

Unfortunately when these break you must take them to a well-equipped and experienced shop trying to change these yourself, or having an ill equipped shop try it will only end in your having to replace the entire circuit board. Which in most cases is the Main PCB. This is a most definite do not try this at home situation.

My best advice of course is to be as careful and as gentle as you can with these USB ports. As I said they are a poor design choice for this gear and break easily.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Technics SL1200 cutting out, or output low on one side

The most common problem we see with the technics SL1200 are the rca output cables failing.SL1200

The original output cables for the SL1200 are no longer available. Due to the strain relief system on these not just any cable will fit. There are however several good quality cables out there that will fit the SL1200, just don’t try to use a super fat cable as you will never get the strain relief back on.

Other than that these tables are almost bullet proof. It is a shame they stopped making these.

Here is a link to a utube video that shows what you would be up against – If you attempt it be sure to use a better soldeing iron than this dude did.   http://www.youtube.com/watch?v=wK9rK6yLR7U&feature=player_detailpage

 

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

BUYING USED EQUIPMENT

In this tech tip I am going to talk about some things to look for when buying used electronic equipment. Buying used equipment can save you big bucks or provide you with big problems if you are not careful.

The first rule is plug it in make it work and test all the functions. If the person you are buying the equipment from does not have the needed equipment on hand to test what ever you are buying, (such as a guitar & cable for and amp, an amp and cable for a keyboard, etc.). Bring your own! When you test a piece of used equipment you are thinking about buying don’t just turn it on play through it and say yea it works I’ll take it. Leave the equipment on for as long as possible.

Many problems take an extended warm up period to show up. Lightly wiggle all the jacks (including the ac adapter jack if it has one) on the unit while it is operating to check for intermittent connections. Lightly tap on the unit in different places while it is running again to check for any obvious bad connections. If a unit is capable of running on both batteries and ac power, check to see that it does indeed work with both. Rotate all the controls while operating the unit, if they are audio controls there should be no erratic behavior or crackling from them if there is, while this is usually not a serious problem it will mean an additional repair expense.

If the controls operate a function as on a keyboard or an effects unit the same applies only the problem will show up in the way the display that indicates that function changes. If a unit has an external fuse check it to see that it matches the value written on the unit. If the fuse that is in the unit is of a substantially higher value or worse yet has foil on it. Insist that the proper value fuse be installed to make sure the unit will operate and is not drawing too much current which could indicate expensive repairs.

If the unit is fairly complicated make sure you get an owners manual with it. If the person selling the unit does not have an owners manual figure on spending an average of $15.00 to $25.00 to get one if it is not available as a free download, as many are these days. Many private parties sell things as is with no warranty, but it never hurts to ask for some kind of warranty (don’t expect too much and don’t be mad if you don’t get it.) If you are buying from a music store expect some kind of warranty. In either case be sure you get the warranty in writing so you are both clear on it. Last but not least get a written bill of sale with the model and serial number of the unit on it.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Where should I buy my tubes?

From a reputable source!

Beware! There are a lot of sources for amplifier tubes and name brand alone does not assure you are getting a quality tube.

You should as a general rule avoid the internet tube warehouse type places because often the tubes they sell are seconds of inferior quality. The initial cost may be cheaper, but the repair bill when they take your amp down will not be. The old adage of you get what you pay for defiantly applies here!

Music stores that sell tubes usually sell what they can buy cheap, sell cheap and make a good profit on. Their choice of what to carry is often not based on careful research. For this reason most music stores are not a good source for tube purchases & information about tubes.

Even some repair shops unfortunately will sell cheap inferior tubes because they feel their customers will kick about the price if they don’t do this. What a good repair shop will do is sell the best quality most reliable tube they can obtain at a reasonable cost to the customer. If this means sacrificing some business so be it, because a good repair shop will realize that quality and long term reliability will save the customer far more in the long run than the small amount of money they would save initially by using cheap inferior tubes!

Sorry if it sounds like I am a soap box here, but I am very passionate about providing quality service and reliable products to my customers.

I will never sell or use something at my shop that is not of good quality, poor quality parts make poor quality repairs, which makes for amplifiers failing in the middle of a gig …and that’s no good at all.

 

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

My new tubes make my guitar amplifier sound so much better; surely this brand must be better than what I had.

Consider the following scenario to illustrate why people think the tubes that they recently had installed in their amplifier whether it be for a guitar amplifier, a bass amplifier, or any other type of tube amplifier are so much better than the brand they had in there before. (In other words how tube rumors get started)

Most people do not change their tubes until they have a repair issue. We find that on a average most tube amplifiers we take in for repair have not had their tubes changed for 2-3 years ! After 2-3 years any set of tubes are not going to sound good in your amplifier. So pretty much no matter what tube is installed now will sound so much better that what you had that you will think the new tubes are best thing since sliced bread. In other words it is not so much the brand of tube that you installed, but the fact that you changed the tubes at all that made the amp sound so much better.

 

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

What Brand of tubes should I use?

Here is a subject that has a lot of misinformation associated with it.

There are some differences in sound between different brands of tubes you may choose to install in your amplifier. For instance as a general rule Groove tubes tend to provide a much harsher ( edgy ) sound particularly in guitar amplifiers, less so in bass amplifiers than say JJ tubes. However aside from the harshness of groove tubes I find that most of the other main stream brands are similar in sound quality. The one place I find a big difference is reliability. The tubes we use here at the shop are all pre tested and burned in for maximum reliability and sound quality. The JJ tubes that we used to prefer to use in repairs have recently dropped in reliability so we have switched to using tung-Sol tube. So far we have been having excellent results with them in all types of tube amplifiers. There are of course NOS tubes and other rare tubes that have a nice tone and a hefty price tag, but in most situations and for most people they are not worth the hefty price tag. When we do a repair we will of course use any tube that you desire for your tube amp repair, but in most situations find that our customers are very pleased with our choice of Tung-Sol tubes for their amp repair.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Tung sol tube

How often should I change my tubes?

Tube picture

If you are using your guitar amplifier or bass amplifier say 4 hours a day 5 days a week = 20 hours per week. Then you should change your tubes every 6 months if you want to maintain the best sound quality. A year ( approx 1000 hours ) should be the absolute maximum on a set of tubes. Yes, they may still light up and produce sound, but it will not be a very good sound.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Do tube amps sound better than solid state amplifiers?

Tube amplifiers seem to have garnered a lot of mystique over the years. I hope to be able to sort from of the fact from fiction for you here.

In my opinion … yes whether they are a guitar amp, a bass amp, a home stereo amp, or the more rare tube power amp they have a warmer sound, great dynamics and a more pleasant breakup than a solid state amp. The downside of course is the higher maintenance cost.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Fender reissue amps

Fender reissue

According to some people the new Fender reissue amps and the originals do not sound the same.

As of this writing Fender Offer the following reissue amplifiers: Fender 65 deluxe reissue, Blues deluxe reissue, Blues deville reissue, 59 Bassman reissue, 63 Fender reverb reissue, 65 Super reverb reissue, 65 Twin reverb reissue.

I have not had one of each in the shop for repair at the same time to compare them side by side. So I can not say one way or the other, but here are some probable reasons. For some tonal differences.

Here are some of my thoughts derived from my experience as an electronic repair shop providing tube amp repair service over the years. In the course of providing tube amp repair on both the originals and the reissues here is what I have come up with.

 

First of all let me state that I think Fender has done everything possible to make them as close to the originals as is possible and to my knowledge the schematic matches between the new and the old units.

Production methods and component quality have changed over the years. Resistors for example are much closer to their stated value than they used to be. Which could account for some of the reason on older amps one amp simply sounded better than the same model from the same year. In other words while the circuits were the same the tolerance factor in early component design meant the circuits operated slightly differently from amp to amp. For example a 100,000 ohm resistor with a 10% tolerance meant the resistor could be anywhere between 90,000 and 110,000 that’s a 20,000 ohm window. Capacitors fall into the same category in regards to tolerance. However before you go out searching for old carbon composition resistors and old style capacitors …. the type of resistor is not the issue it is the fact that the values varied. Carbon comp resistors are also much nosier than the new film resistors. As far as capacitors go you do not want old capacitors as they go bad just sitting on the shelf. The electrolyte in them dries up. Other possible differences may include the manufacturing process and materials used in the transformers. As well as materials and processes used to manufacture the speakers. So in summation The new reissue amps are going to all pretty much sound the same from unit to unit. The old original amps are going to have tonal variations due to looser component and manufacturing tolerances. If you want a Fender 65 deluxe , Blues deluxe , Blues deville, 59 Bassman , 63 Fender reverb, 65 Super reverb, 65 Twin reverb or any one of the other many fine amplifiers that fender has produced. Even if you buy an original it will not necessarily sound as good as your buddies down the street does. Can you tweak the new ones .. of course. There are after market transformers, speakers and different tubes that are all going to change the way it sounds. If you want one to sound the same as your buddies original down the street. You are going to have to get your buddies and yours and bring them both in to the shop. Then every resistor and capacitor will have to be measured in his and the ones in yours that are a different value due to tolerance will need to be changed to match. If after that the sound is still not where you want it. Then it would be time for the after-market output transformer, then a different speaker, and possibly different tubes. Then if it still did not sound as good we would know it was just the magic from the 60’s that made them sound so good

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

Sticking keys on Yamaha keyboards

Sticking keys on Yamaha keyboards

I guess all good things must come to an end.

Yamaha has just informed us that as of 1/1/2014 they are no longer providing no charge replacement keyboards to correct sticking keys.

So if you have sticking notes they will need to be individually repaired at your expense.

If you have a Yamaha keyboard with sticking keys, stuck keys, or sluggish keys there is a possibility that you can have a new keyboard installed in your unit for just the cost of the labor.

There are way too many models affected to list them all here. So if you have a Yamaha keyboard with sticking keys go to our website www.asmusic.org at the top of the page you will find a Contact link, click that link, and then click our email link to email us the Model and serial number of your Yamaha keyboard. We will then check with Yamaha to see if it qualifies and email you back the results.

By the way you do not have to be the original owner to take advantage of this, Also you would be surprised at how old some of the models they are covering are. So even if your keyboard is pretty old it is still worth checking into.

Don’t forget to visit our website: www.asmusic.org when you get a chance.

Randy Morgan …..  Owner & head technician at All Service Musical Electronics Repair

IMG_0097

When comparing labor rates are you comparing apples to apples, or apples to Kumquats?

Apples

We charge $77.50 per hour here, which for the level of experience, the efficient manner in which we are able complete the repair, and the quality of the repair work we are able to provide in my opinion the best deal in town. 

What is the effective labor rate you are paying, that lower price that other shop quoted you sure sounded good .. But is it really? 

A lower level of experience may actually mean you pay more for your repair.

An experienced well equipped shop may complete a repair in an hours’ time that may take a less experience poorer equipped shop and hour and a half to accomplish. So if the less experienced shop is charging 60.00 an hour you are in effect paying them 90.00 per hour.

If a shop is not factory authorized for most brands they will not have access to all the factory service materials.

This will again cause them to spend more time than needed to repair the unit and again increase the effective labor rate you are paying.

Sadly, some shops quote a lower labor rate and a quick turnaround time to get you in the door, but then actually charge a higher rate, and then take longer than quoted, sometimes much longer to complete your repair.

I was on good terms with a tech that used to work out of Showcase Music, and he freely admitted that he engaged in this practice. Many shops will also give low ball estimated repair cost on the phone just to get you in the door, but then will find a reason to charge you more, sometimes much more.

I hope you found this information useful and encourage you stop in sometime and check us out.

 

Randy Morgan

Owner