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AR3a's and Fisher X202-B Integrated Amp


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My first post was several weeks ago when I purchased a pair of 3a's from a used furniture store (the ones painted white). The planets must be in alignment for me as my dad (80's)recently told me that an old friend was moving out of his house into an apartment and did not want his old stereo. So my dad took it and I will be picking it up this month. It is a Fisher X202-b integrated amp, FM-100-B Tuner,and a Thorens TD-124 turntable. There are no speakers with it. Supposedly it has only one owner and it works.

My question is can I, or should I, hook this system up to the AR3a speakers? They are currently connected to my modern Yamaha receiver which has 35 wpc and although it sounds clear, doesn't seem to have much horsepower.

I have read postings from a gentleman named Jerry regarding bi-amping, and wonder also if I could do it with my Yamaha and Fisher. I have to admit though I would not know how to do it (make the connections) even if it were possible. I have read many posts on bi amping but the picture is still somewhat fuzzy on how to do it.

Thanks for this website and any help you can provide.

Mike

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Hi Mike;

Your very lucky.

The Thorens TD-124 was and is, a state of the art turntable, with an optional arm.

An arm by Shure, model SME-3009 was the most common arm I saw in photos with an Shure V15 Type 2 cartridge installed.

The AR speakers are top notch irregardless of the cabinet finish or condition.

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>My first post was several weeks ago when I purchased a pair

>of 3a's from a used furniture store (the ones painted white).

>The planets must be in alignment for me as my dad

>(80's)recently told me that an old friend was moving out of

>his house into an apartment and did not want his old stereo.

>So my dad took it and I will be picking it up this month. It

>is a Fisher X202-b integrated amp, FM-100-B Tuner,and a

>Thorens TD-124 turntable.

>

>My question is can I, or should I, hook this system up to the

>AR3a speakers? They are currently connected to my modern

>Yamaha receiver which has 35 wpc and although it sounds clear,

>doesn't seem to have much horsepower.

>

>I have read postings from a gentleman named Jerry regarding

>bi-amping, and wonder also if I could do it with my Yamaha and

>Fisher. I have to admit though I would not know how to do it

>(make the connections) even if it were possible. I have read

>many posts on bi amping but the picture is still somewhat

>fuzzy on how to do it.

>

>Thanks for this website and any help you can provide.

>

>Mike

Hi, Mike!

Read your post and did a little research on the Fisher X202-b. It's a tube set and normally you cannot "Jerry - rig" your AR's with a tube set. Mike, this is really your lucky day, however. I reviewed the Fisher schematic and it looks as though you are in luck!

Now, before I go further, you can ALWAYS bi-amp with ANY amp if you take the time to separate the xovers and bring out an additional terminal. If you have the time and the patience and don't mind modifying the external speaker boxes, this is the way to go.

When we "Jerry-rig", we use ONLY the three existing terminals on the AR-3a. The way this works is just about every solid state amp has a common ground for the black speaker terminal on the amp. So, we use two amps and connect both commons to terminal 1 on the AR’s.

Then the red speaker terminal on the amp gets connected to terminal 2 for the woofer amp and terminal "T" for the mid/tweeter amp. (Naturally, we remove the strap that wires these two together. If you decide to return to a single amp configuration, all you have to do is replace that strap.)

It appears that the Fisher integrated amp will work in this scheme, but it would be a good idea to measure with a resistance meter (DMM or analog) … just to be sure.

Mike, you have the absolute idea situation for a bi-amp. The Fisher tube amp is rated at 20 watts per channel and is NOT a good match for driving AR-3a's by itself. Actually, many folks will say the 35 watt Yamaha is also on the “light” side. If you listen at moderate levels and have the Yamaha driving just the woofers, I think you’ll be fine.

The beauty of bi-amping the Fisher and the Yamaha is that you get the best of both worlds. The ss Yamaha amp driving the current hungry woofers and the Fisher with it’s "silky" high frequencies (even harmonics) powering the mid-range and tweeter.

So, Mike, you need to decide, between two options:

1. separate the xovers and add a 4th terminal

2. Jerry-rig and leave the internals of the speakers alone

Regards,

Jerry

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Vern and Jerry, thankyou very much. I tried to draw a picture to visualize the connections but my lack of knowledge is killing me. I have some questions but please answer at your leisure.

From the Yamaha receiver, there is a red/black going to speaker A, and a red/black going to speaker B. Starting with this amp only, do I take one black and go to speaker A terminal 1, and the other black to speaker B terminal 1? This would leave the reds on both lines dangling at each speaker.

Would I then do this with the Fisher amp, in effect doubling the black wires on each terminal?

Sorry guys for having to take this one step at a time. The lightbulb will go on soon, I hope!

Thankyou very much. Mike

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Mike, the connections are NOT hard. Don't worry about that now.

If you want to try the "Jerry-rig", we first need to find out:

1. whether the Fisher amp works - just connect to your AR's in the normal fashion (although you'll find the Fisher a lot different than your Yamaha). Then see if you can get undistorted sound at moderate volumes.

2. whether the Fisher amp really is compatible with the Yamaha. Do you have access to an ohm meter (either VOM or Digital Multimeter)? If not, can you borrow one?

Before we connect speakers, we should be certain that the amps really will work together. According to the schematic, it's a fit ... but ... but sometimes manufacturers introduce variations that are not documented.

Mike, when will you get the Fisher amp?

Regards,

Jerry

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Jerry: Thankyou for the guidance. I will be getting the Fisher equipment on Saturday and will try to get a hold of a digital multimeter by then.

Since I haven't seen it yet, I tried to look up pictures of it on the internet. It appears that I can connect my CD player to the back of it for the test run.

I will post on Sunday to let you know if things are working or not and will continue to research previous postings.

Thanks Mike

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That's a good plan, Mike.

As for your CD player try connecting to the Fisher via the AUX-2 (Tape) input. I want to see whether you get enough voltage this way to get a decent output signal.

If the output signal is too low, then try Aux-1, but then you must use the Low Level volume control in addition to the Main volume.

With the DMM I want you to measure the resistance between the 4 ohm speaker output connection and the ground connection (outside part) on any input jack. What we are looking for is zero (or very close to zero) ohms. This means that the 4 ohm output is ground and confirms it will work under the "Jerry-rig".

Regards,

Jerry

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Hey Jerry: I picked up the Fisher system and Thorens turntable and was quite suprised to find a very clean system, almost looks new. It appears to have all the original cables. Also, it came with a folder that contained all original borchures, operating instructions, spec sheets, etc. On the warranty card, the owner wrote in that it was purchased 2-2-63.

In the operating instruction book, on the last page, it has a section called Technical Specifications. Next to 'Music Power Output', it says "80 watts both channels (IHFM standard)" So maybe it is really 40 wpc. If it is then it is more powerful than my Yamaha @ 35 wpc.

So, I hooked it up to the 3a's, put the amp on the 4 ohm setting, put the cd player in AUX 1, and viola, it sounded ALOT louder than the Yamaha, and I hardly had to turn the volume knob up. What a difference. My wife said it was the first time she ever felt the bass rumble her feet.

My friend never showed up to work end of last week so I never did get the DMM. I might make a run to Lowes today to see how much they are.

Thankyou and I will let you know. Mike

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>In the operating instruction book, on the last page, it has a

>section called Technical Specifications. Next to 'Music Power

>Output', it says "80 watts both channels (IHFM

>standard)" So maybe it is really 40 wpc. If it is then

>it is more powerful than my Yamaha @ 35 wpc.

>

>Thankyou and I will let you know. Mike

Hi, Mike!

That Fisher amp is rated at 15 watts per channel (rms). The "Music Power" and IHF ratings are NOT the same and always significantly higher than the rms rating. (RMS is a standard the Federal Trade Commission mandated sometime in the early 70’s as manufacturers were totally confusing the public. Your Yamaha is a much more powerful amp.)

Your tube amp could easily be putting out more voltage, but the current drain on the AR's will eventually cause the rails to sag and result in clipping distortion. Just be careful, because it’s NOT a good fit … it will, however, become a great fit!

OK, first you measure the resistance between the 4 ohm output and the ground shield on any input jack on the Fisher. You should read zero or very close to zero.

Next measure the resistance between BLACK speaker output on the Yamaha and the shield on any input jack … again you should read zero.

One last test measurement, connect an audio cable between TAPE OUT on the Yamaha and AUX-2 on the Fisher. Now measure the resistance between the 4 ohm speaker output on the Fisher and the BLACK output on the Yamaha. Again we are looking for a very low reading (make sure the speaker switch is selected on the Yamaha).

At this point we are ready to hook up the speakers.

The BLACK speaker output lead and the 4 ohm speaker lead get twisted together AT THE SPEAKER and go to terminal 1

The RED output lead goes to terminal 2 on the speaker (woofer)

The COMMON output lead goes to terminal T (tweeter)

Now, before I go on the connections above work for the RIGHT channel. The LEFT channel on the Fisher is a bit different. Again you always connect the 4 ohm output to terminal 1. There is a speaker impedance lead that you must disconnect and tape up. (This allows you to reverse phase, which is something we just can’t allow). Then the COMMON lead, which goes to T on the LEFT channel, is the connection just right of the GND connection. That is, it’s NOT the connection next to the 4 ohm as in the RIGHT channel. You need to skip one terminal.

Now, once everything is connected, turn both volume controls full OFF. Power on both units and select a source on the Yamaha (CD, tape, FM, etc.). Then slowly bring up the volume on the Fisher (select AUX-2 as the source) and you should hear sound in the mids/ tweeters on both sides. If NOT double check all connections.

If you hear sound, turn the volume down and then slowly bring up the volume on the Yamaha and you should hear the woofers groaning. If you do, then slowly bring up the Fisher until the sound is balanced.

Mike, let us know how it sounds …

Regards,

Jerry

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Hey Jerry: Hope the Holidays are going well.

I have a bit of info and need some clarification.

Although I am not part of that group, I was reading posts from AudioKarma and there are two postings talking about the Fisher X202B. According to these posts, if it has 6BQ5 tubes, then it's 15 wpc. If it has 7591 tubes, then it's 30 wpc. Mine has the 7591 tubes, so I'm still hoping (maybe wishing) that I have around 30wpc.

In anticipation of the DMM tests, I tried to put a schematic together for the speaker hookups. When I read your directions, it seems clear. However, when I face the back of the two amps and see the 8 ends, I can't figure out which ones get twisted together from what amp, and how they go to the 6 terminals.

I must be thinking about this too much as I can't get it. I am using the speaker wire that is connected and split at the ends, showing a red wire and a silver wire. I apologize in advance for having you go through this again, but could you maybe start with the Yamaha, which has a red/black/black/red on its backside, showing +/-/-/+, above the wire attachment, and go one line at a time to the speaker terminals, and then do the same for the Fisher? Being very new to wiring and connecting amps, I don't want to get the wires crossed incorrectly and mess something up.

Thankyou Mike

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>Hey Jerry: Hope the Holidays are going well.

>

>I have a bit of info and need some clarification.

>

>In anticipation of the DMM tests, I tried to put a schematic

>together for the speaker hookups. When I read your

>directions, it seems clear. However, when I face the back of

>the two amps and see the 8 ends, I can't figure out which ones

>get twisted together from what amp, and how they go to the 6

>terminals.

>

>Thankyou Mike

Mike, I hope the pic below clarifies the connections. Clearly the woofer amp is pretty straight forward. You can see the red and black terminals in the pic.

Just remember the line connected to the BLACK speaker output goes to terminal #1 on the AR-3a. The line connected to the RED speaker output goes to terminal 2 on the AR-3a.

On the Fisher, it’s a little different. The 4 ohm output terminal goes to terminal #1 on the AR-3a and here is where you twist the wires together – right at terminal #1.

The other speaker line goes to terminal “T” on the AR-3a. It’s pretty easy for the RIGHT channel on the Fisher as you just connect the common to “T”. For the LEFT channel you connect the speaker terminal next to ground to “T” – NOT the terminal that is next to the 4 ohm as in the RIGHT channel.

Try connecting just the woofer and then turn the Yamaha ON and verify that just the woofer is making sound. Then do the same with the Fisher, but verify that only the mids/tweeters are producing sound.

Hope this helps …

Regards,

Jerry

http://www.classicspeakerpages.net/dc/user_files/1818.jpg

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Jerry: A friend came over last night and brought his multimeter (not a digital one). I've never used one and don't know quite had to read it but he claimed that doing your tests showed no high values. So, I took a chance and hooked up the system per your instructions. Woofer amp (yamaha) first, check. Tweeter amp (Fisher)no check. Only the right side worked. Double checked connections and felt they were all good.

I started to disconnect and reconnect one thing at a time to maybe get the other tweeter going. My first shot at it was to reconnect the speaker impedence lead back to the 4 ohm terminal. Once I did this, both of the tweeters now worked. There appears to be no affect on the bass.

There appears to also be a little bass coming from the Fisher (tweeter) amp, not much, but I can faintly hear it as I increase the bass (knob). I will check today to make sure that no wires are touching.

Jerry, thanks for you help in this procedure. As a novice, trying to describe the new sound, I would say that it is "full", compared to when it was just running off of the Yamaha, or just on the Fisher. It is not a 'loud' sound (no matter how high I turn up the volume knob, it just doesn't want to 'let loose'), but appears to be very clean. I'm finding it somewhat neat to be able to adjust each amp and taylor the bass and highs. I'm tempted to put the impedence lead on the 6 ohm terminal. Do you know what this would do if anything to the sound?

Any other hints that you or others could offer would be greatly appreciated as I enjoy my new biamped, multigenerational, system.

Thanks again, Mike

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>Jerry:

>

>Jerry, thanks for you help in this procedure. As a novice,

>trying to describe the new sound, I would say that it is

>"full", compared to when it was just running off of

>the Yamaha, or just on the Fisher. It is not a 'loud' sound

>(no matter how high I turn up the volume knob, it just doesn't

>want to 'let loose'), but appears to be very clean. I'm

>finding it somewhat neat to be able to adjust each amp and

>taylor the bass and highs. I'm tempted to put the impedence

>lead on the 6 ohm terminal. Do you know what this would do if

>anything to the sound?

>

>Any other hints that you or others could offer would be

>greatly appreciated as I enjoy my new biamped,

>multigenerational, system.

>

>Thanks again, Mike

>

Mike, NO! Absolutely no! You cannot change the impedance on the Fisher. Only the 4 ohm lead can be connected to terminal 1 AND to the Yamaha. Any other connection could damage the Yamaha.

What you can play with, Mike, are different inputs on the Fisher; like Aux-1 - this might give you slightly more, but possibly too much voltage.

Congratulations Mike. You are the very first person to "Jerry-rig" your AR-3a's with a tube amp! Everyone else uses solid state amps.

Now, you have successfully completed stage 1 of the "Jerry-rig".

STAGE 2 consists of further performance increases at both ends. Specifically, what we do next will give you better bass and clearer/cleaner high frequencies.

The first step is to turn down the Fisher and with the Yamaha running turn the treble control from end to end. You should hear no difference in sound. So, turn the treble control full OFF.

What this does is:

1. reduce the chance of harmonic distortion as we are no longer mixing fundamentals with harmonics in the Yamaha

2. gains you significant headroom in that amp (means the amp is now capable of putting out more clean power)

Next step, is to do exactly the same with the bass control on the Fisher. Again, by turning the bass control full OFF (actually I set mine at 9 o'clock as I need just a tad of mid-range - it really depends upon the center frequency of the bass control), you:

1. reduce the chance of harmonic distortion as we are no longer mixing fundamentals with harmonics in the Fisher

2. gains you tremondous headroom in the Fisher (means the amp is now capable of putting out a ton more clean power) Don't forget to turn both pots to max increase - no need to waste power since you control balance of sound now with the amps!

Last step in STAGE 2, improves the bass by providing the woofer with more return options. What you do is get a small piece of lamp cord (2 to 3 feet). Strip all four ends. Then at the amp twist the lamp cord together with the black leads on the Yamaha (notice that if you look closely the lamp cord usually has a ribbed and a smooth side – ribbed to right is the simple rule). Now the other end of the lamp cord, you twist together with the 4 ohm terminals on the Fisher. What we are doing here is allowing the woofer more options for return current as speaker selection switches often add resistance (see new pic below).

Let me know, Mike, how it sounds.

Regards,

Jerry

http://www.classicspeakerpages.net/dc/user_files/1819.jpg

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Hey Jerry: I tried phase II with the lamp cord and the sound did not appear to be better to my novice ears. But then I tried to use the FM radio, and I only got the tweeters, no bass. Rather than get frustrated, I went back to square one.

1. Used the Yamaha amp only. Not a strong sound at all. Had to turn the volume knob up to around 1 o'clock just to get decent listening sound.

2. Then connected just the Fisher amp. Much fuller, richer sound. Only had to turn the volume knob up to about 10 o'clock to get good room filling, big bass sound.

3. Then did the bi-amping. The sound fell somewhere in between 1 and 2 above. I now had to turn the volume knobs on both up to around 1 o'clock so get some good listening action.

So, I am now back to using the fisher amp only. All that I can think of is that there must be some sort of compatibility issues between the 1963 amp and the 1998 amp, with the Yamaha winning the battle.

I have started a file of sorts and your colored diagrams will be taken care of as I continue my new hobby.

Thanks Mike

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Mike, sounds like there might be something wrong with the Yamaha.

Did you attempted to connect the Fisher in the bi-amp with any of the other connections besides the 4 ohm terminal?

The Yamaha should be able to send solid bass to the woofers in the 3a's without having to turn the volume way up. Any chance you turned the bass control on the Yamaha full OFF?

How did you connected the source to the Yamaha? Are you going through the Fisher first?

Have you noticed any difference in the Yamaha since you started bi-amping?

Regards,

Jerry

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  • 4 weeks later...
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Hi all, I wanted to pass on something I just discovered on my new system. I finally got around to reading the X202-B manual. One of the buttons is called 'Loudness Countour'. The manual says that it will, in part, raise the highs and lows. So, I just flipped this button, and the sound exploded, not as in turning up the volume, but as in color/clarity.

When I now listen without the loudness contour, it sounds somewhat weak. I really can't believe that on a 1963 amp pushing AR3A's, this one button has made a ton of difference with the lows AND the highs.

I now listen with this button flipped most of the time.

Thanks Mike

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Hi, Mike!

Just about all decent systems have a loudness contour switch. Purpose of this switch is to compensate for non-linearities in human hearing.

That is, at LOW volumes we don't hear either high frequencies or low frequencies so well. At very low volumes we can hear very well in the mid range (where our wives voices will be and where we'd hear animals moving about).

Now, the way most of these work is they are connected directly to the volume control. So as you turn the volume UP the emphasis in both highs and lows is diminished.

You should be able to achieve pretty much the same sound with the tone controls. Problem with the tone controls is the "boost" is present for all volumes.

Regards,

Jerry

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