Mating a Fisher 440 Amp to a 490-T Tuner

Gadget;
Yes, shielding may be in order too. In fact it may be beneficial to place a metal shield above the 440-A chassis to also deflect heat too. A fan for cooling may be in order too. Whatever works is my motto. Some experimentation is necessary in order to obtain the best results in any case. In the original cabinet environment there was plenty of space between the 440-A chassis and any record changer. That will not be the situation here.
Joe
 
Joe; A baking sheet cut to fit and mounted on the framing between the bottom of the tuner and amp, and the TT, allowed to ground to the chassis frame should provide adequate RF shielding and heat reflection from the TT.
Larry
 
Larry;
Thanks for the suggestion about a baking sheet - they are usually less expensive than equivalent sheet aluminum at the hardware store. What would really be nice would be some mu-metal to use as shielding, but not easy to find. This used to be a common metal to find around the bell of the backside of color CRTs in RCA and other brands of color televisions. Most of these shields have long since been thrown away along with the complete set.

Today I made some real progress on assembling the framework for the two chassis to fit in. I added the upper horizontal frame pieces and fitted the 490-T chassis as I went. I did have to cut one notch of a horizontal frame piece at the rear to make room for better access to the RCA jacks on the back of the 490-T. It was not a problem to do this and does not weaken the frame piece significantly as the notch was only about 1/4" high and about 2 inches long. I added corner reinforcements at the bottom of the cabinet framework. I installed the 490-T chassis and experimented with position of the 440-A chassis. There is plenty of room and cable length to move it about for least hum if that develops as an issue when I get around to checking that aspect of performance.

I secured the record changer base to the framework and then added an aluminum strip to cover the edge of the changer base where it meets the edge of the 490-T faceplate. They differ in height by about 3/16" and this floor threshold aluminum piece was handy from some previous work and covers the area nicely. There are 9 wood screws holding the front, left and back edges of the changer base to the framework.

I think I will sand the changer base once more and change the stain I used. It needs to be less dark and somewhat more yellow in tint. The 490-T faceplate is more difficult to match than I first thought. The stain I picked cured darker and more red than it looked when I first started working with it. I may have to mix some other color of stain with what I already have to get closer to the desired color. The outside of the cabinet need not necessarily be an exact match. I will see what else I can find and experiment with test samples first.

Here are some pictures of what it looks like so far.

Joe
490-T on Frame web 06.jpg 490-T on Frame web 07.jpg 490-T on Frame web 08.jpg
 
Today I bought more plywood to use for the exterior of the cabinet. I also bought some Minwax Early American stain to mix with the English Chestnut and Red Mahogany to develop somewhat of a yellow cast to match the faceplate of the 490-T part of the cabinet interior. I mixed several trys and found one that satisfied my eye, which may not be perfect but seem to be a better match than what I began with.

I removed the changer wooden base and sanded its surface, then I applied some of the stain I had mixed. It is now drying. As part of the adapting of a wooden base for the Elac Benjamin Miracord 40H, I had to enlarge the holes I had originally drilled for the spring seats of the changer. It turns out that this changer with its original plastic base has 4 rubber spring seats that hold the springs and consequently the changer in the correct position side-to-side and front-to-back. Not only does it position the changer in those directions, it also lifts the changer such that its top stamped plate rises above the wooden (or plastic) base enough to clear that surface by at least 3/16" or a little more. So for this particular changer the rubber spring seats are necessary from several positioning standpoints in order for it to work correctly. Here are pictures of one of the rubber spring seats:
Changer spring seat web  01.jpg Changer spring seat web 02.jpg
so, for now the wooden changer base is set aside after the application of the stain I used. Tomorrow I plan to determine just how high the cabinet walls will have to be to enclose the changer and clear the top of the automatic spindle comfortably. With that dimension determined I can proceed with cutting the plywood for the front and sides. I also bought one board to use as the back support for the top of the cabinet. This is a solid piece of wood to go all the way across the top rear portion of the cabinet which the torsional hinges will mount to and support the top.

The overall dimensions of the frame before applications of the sides and top are 26 1/8"W X 16 1/4"D X 13" high. It will be interesting to see what the total weight will be. The changer seems to be the heaviest part so far. That cast metal piece for the turntable is quite heavy and with the rest of the changer is probably about 25 to 30 lbs. I am pretty sure I will need to add some sturdy handles on either end of the cabinet for ease of handling it in moving.

Joe
 
IIRC the Miracord platter weighs around 6-8 lbs. It's definately a heavy sucker.
 
Larry;

Yes and by the time it is combined with the rest of the changer it is pretty heavy. Average weight seems to be about 6.4Kg so that equates to about 14.1 pounds - less than I thought, but still heavy. The worst cases are the old changers from the 1930s and 1940s which had really thick steel.

I went back out to the barn to check on the stain and it looks good. There is still some wetness which should be gone some time tomorrow. I won't be doing anything more on the changer base than to smooth the surface and then apply some lacquer after it dries well. I can still proceed with the measurements of the changer spindle height even before that and probably decide on the full height of the sides and front. The rear board that will support the hinges will be cut and mounted to the correct height first, then the front and sides. I might get lucky and manage to get the cabinet together except for the top by the weekend if I get lucky and work goes quickly enough.

Joe
 
Here is a snapshot of the unit with the changer in place and the tall automatic spindle in place.
Changer with auto spindle web.jpg
Here is a picture with the changer, automatic spindle and the 490-T with all its knobs in place. The changer base has its lacquer coat in this picture too.
Changer with base 490-T web.jpg
I am off in search of another piece of plywood large enough to take care of the cabinet front panel.
Joe
 
Cool, a mini-console. Planning to add handles or something to make it a little easier to transport ? Thinking something on the sides, though it would have to be cosmetically appropriate, not some big ugly band gear handle type thing.

What speakers go with it?
 
Gadget;
Yes, some sort of decorative but useful handles so that my granddaughter and one other person can easily carry it without having to worry about dropping it. I am going to have to search to see what I can find. I am like you, I don't want it to be clunky and ugly like the typical band devices.

I bought some Fisher XP-55B speakers to go with it and they sound nice paired with the amp and tuner chassis. They are large enough to sound decent but not so large that they are too heavy.
XP-55B Speakers web.jpg
Today I made another excursion to the hardware store for a few more pieces of plywood for the cabinet. I found some that exactly met what I was looking for. The front and sides will have vertically aligned grain as is usually seen with professional cabinet work. The top will have its grain oriented from side to side. There will be edge trim around the top and also where the sides meet the front. I have noticed there are some Fisher badges available on eBay and I might get one of those to put on the front of the cabinet.

Joe
 
Those look a lot like the Utah speakers I have out in the garage. Wonder if they are actually the same.
 
Gadget;

I seem to remember that Fisher used Bill Hecht in NY to make his speakers. They began with the XP-1 speakers and were acoustic suspension types and incorporated copper shorting rings to reduce distortion. Bill continued to provide speakers to Fisher for a good number of years.

Joe
 
The 55B's were too late for the Hecht Treatment. My 55B's have CTS drivers in them.

That cabinet is coming along quite Nicely Joe. I'd make one like that but I can't draw a straight line with anything except a scalpel! Grand daughter will love it.

Larry
 
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Larry;

I did not know when Fisher began to use speakers other than Bill Hecht's units. At least they are Fishers. They sound pretty good with the 490-T and 440-A amp combo. In years to come if my granddaughter wants better speakers, that is always an option. There are lots of choices available.

Today I cut the 1/2 inch birch plywood pieces for the sides and the front of the cabinet. I do not have a table saw, so what I did was use a T-square that is normally made for use with sheetrock to make nice straight scores through the surface paper layer and then a sharp pop with the hand and sheetrock snaps along the scored lines. The T-square has a knob that allows the right angle short piece to be removed from the long straight edge. It is an all aluminum tool and I used the long piece to mark off and draw a straight edge for the dimensions of the panel pieces I needed. Then I measured the distance from my saber saw blade to the straight edge at both ends of the panels I was cutting. I set it up to cut the pieces at least 3/32 beyond where the actual final dimension would be. All the initial measurements were done from the factory cut straight edges of the plywood. I was using 2' X 4' pieces from the hardware store. I clamped the straight edge and double checked the blade landing point at both ends before I began to cut. The left edge of the saber saw foot was kept snugly against the straight edge as I cut. The resulting cut is almost as perfectly straight as a table saw can do. Using a relatively fine tooth blade in the saw helps a great deal to eliminate chipping and fuzziness of the cut.

After each piece was cut, I moved it to my belt & disc sander and carefully sanded the edge down until I had the edge at the pencil line I had drawn for the piece. A bit of final sanding with my hand held orbital sander allowed me to get a good fit between the sides and the front. It took me all morning just to get to the point of placing and fitting the front to the sides on the cabinet frame. Even the cabinet frame needed some final sanding to eliminate some errors in shape. Nothing I ever do is perfect anyway. I can cover up the remaining minor errors with some mitered trim on the front to cover the edges of the sides. I am gradually getting better at this as I go. I figured the best approach overall was to work from the inside out, making good use of tools set up for right angles instead of trusting just measurements with my tape measure and rulers.

I reached a stopping point about noon and came in to eat lunch and feed Mr. Leo, our cat. He is now lying across my legs as I write this from my recliner. I may not get up for an hour or so of nap-time. Standing on my feet all morning was a bit much, and now I need a rest. I will take pictures once I get the pieces attached to the cabinet frame, stained and ready to add front trim.

I ordered a new AC switch for my 500-C from Mark Oppat, which came in the mail yesterday. The switch failed open and although I could just change to using the accessory contacts to turn the 500-C on, I decided to get a new switch while they are still available. Even though the old switch has one section bad, the other is still good and I will not throw the old one away. Mark includes an instruction sheet with the switches which is helpful in the installation of the new switch on the old volume control assembly.

Joe
 
Before I began work on the 490-T and 440-A chassis I noticed that neither chassis has a bottom cover. I have seen some products years ago which had a metal shield plate that would ground to the chassis when fastened down in the cabinet. I am wondering if Fisher did this or if they did not find it necessary.

Thoughts?

Joe
 
I don't have a table saw either. I made a saw board for my circular saw to stand in.

62514.jpg


mine looks slightly different but you get the idea. The measurements aren't critical, one pass with the saw takes off the excess and makes the edge of the guide be where the saw is actually going to cut.
 
Gadget;

That's a nice way to do it. I had not thought of using wood to make such a cutting guide. I do have a circular saw, but seem to have difficulty keeping it going straight even with a straight edge. Its an older Craftsman saw. I have had trouble with the circular saw getting caught in the material and kicking back, hence the move to the saber saw.

I have used a table saw a few times at my friend's house but it is about an hour's drive into another county, so I don't do that often. I also hate to bother him about such matters. I have seen a few table saws that I like, but since I don't do too much cabinet work I hesitate to spend the money it would take to get a decent one. I have been watching for estate sales that might include one where I might have a chance of getting a good quality used one. One major issue for me is that because of my bad back, I cannot deal with lifting a lot of weight. That would mean that I would have to get some younger able bodied men to go with me if I were to buy such and item and let them do the loading and unloading of the saw and any accessory material tables. Then again, I have difficulty in lifting and dealing with 3/4 inch 4' X 8' plywood sheets, so maybe a table saw would not be a good idea anyway. If I manage to get this task completed with some degree of success, I will consider myself lucky. The belt sander and orbital sander let me get a much better fit between pieces even if my assembly is not perfectly straight. I try them against each other and if there is too large a gap I apply sanding effort until the fit is better.

I may get the sides and front assembled to the cabinet frame on Monday. After cutting the plywood pieces today I have some nice boards to use with my clamps while glue dries. I like to use a combination of wood screws and glue whenever possible.

Joe
 
Mine is also a Craftsman, guessing its 15 or so years old. Finer blades seem to help in plywood. The low tooth count framing ones really snag on me. Not sure what I'm using on it currently but it may be a 40 tooth. They make actual proper plywood blades that are in the 100+ tooth count range. Fine cuts, but slow going.

My radial arm saw I think has an 80T in it and it does nicely. Ripping on one of those is really dicey just because of how they work. I've done it solo with large sheets but you really need to build it into a long workbench for doing that kind of thing.
 
Gadget;

I tried using my Craftsman circular saw and I believe I need to get a new set of blades. Some of them have become dull and should be replaced. I probably should get a 60 tooth and one higher for finer cuts. I can see where a radial arm saw would have issues if dealing with a 4' X 8' sheet of plywood if the work table was not long enough. With a table saw you have the issue of feeding the material and supporting it when working with large sheets of plywood. Extension tables with rollers become necessary. As long as i can manage with what I have I will make do. I did invest in a nice set of countersink drill bits with adjustable collars recently. These have been really helpful in the work on this cabinet.

One thing that has been very helpful is the availability of 2' X 4' and 4' X 4' precut sheets of furniture grade plywood of various types. There are also pre-cut lengths of various solid boards that I have taken advantage of too. The framing for this cabinet was made from some of those. The wood I used for the framing is poplar wood. It is relatively easy to work with.

Joe
 
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