Spec -2 AWH-045 board relays RL1 / RL5 & RL2 / RL6

[markthefixer]

Well, I got a PM looking for private help again. As a note: I do copious PUBLIC help, and reject private requests.

But since the requester was a long time member, and the subject matter arcane enough, I decided to get it all out there, in public, and hopefully easily found during a search.

I think I will do the anonymous route, to protect the guilty. <grin>

----------------------------- the request : --------------------------------------------------------------------------------------------
Hey man I've been seeing your input around the pioneer forum and thought it worth a try to ask...

How do you clean the reed relay...like can it be done w/o destroying it?

I've got the notably rusty sheet metal covers off and spray attacking with deoxit but can't be certain any chemical is being delivered to moving contact...

The right channel must be turned up high vol to get the relay to engage as it is...

Is this part available or a better replacement...

--------------------------- end of the request ----------------------------------------------------------------------------------------

I don't do private help, I do plenty of PUBLIC help. Thus it CONTINUES to help people hereafter.

Wikipedia also supplies the answer:

A reed relay is a type of relay that uses an electromagnet to control one or more reed switches. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them. Sealed in a long, narrow glass tube, the contacts are protected from corrosion.

Sealed in a glass tube. NO cleaning POSSIBLE.

I surmise you are referring to muting RL1 / RL5 single reed relay ASR-017. This part is a known troublemaker, and is a "replace upon sight". This is a better fit for your question.
The other reed relay RL2 / RL6 (ASR-005) is a dual reed relay which only operates when 4 ohm speaker loads are selected.

RL1 (RL5) is a spst (aka: 1 FORM A ) 24v reed relay ASR-017. It carries 26mA in the front end of the Spec-2 amp, doing a muting function.
https://www.mouser.com/ProductDetail/Littelfuse/HE751A2400?qs=X8LBAgEWIKJBfoi7amFn0Q==

RL2 (RL6) is a dpst (aka: 2 FORM A ) 24v reed relay ASR-005 that shifts the current limit voltage levels down from an 8 ohm output load to a 4 ohm output load.
https://www.mouser.com/ProductDetail/Littelfuse/HE722A2400/?qs=X8LBAgEWIKJTn4NQ/9P2xA==

Searches through the threads on the ASR-005 should provide a multitude of other DPST / 2 FORM A 24v replacements.

There should be even more replacements available for the ASR-017 single reed 24v relay.

They may not fit into the PC board holes. In his thread Echowars does the "dead bug install'
where
the relay is glued onto it's back, legs pointing up, and flying wires go from the legs to the appropriate pcb pad.
Others have made adapter boards.
neither is mandatory, both work.

Oh, and between the Amp board (AWH-045) board schematic and the unit (Spec-2) schematic they couldn't keep their nomenclature straight in the Service Manual, so I used BOTH labels to eliminate any confusion.

Those parts links are to Mouser stocked major manufacturer's relays that have parts numbers that have endured for many years, and are currently in-stock. Between 2 and 3 bucks currently.

 

[markthefixer]

ASR-005 dual relay teardown pics:
(IT WAS JUNK...)







saving for future work / implementation mtf 11/22

 

[Shikaka]

Here's a dissected SPST ASR-017 (RL1/RL5) from my Spec-2 rebuild last winter. I suspect it came from the same manufacturer as ASR-005.

 

[zebulon1]

Those hair transformer wires could corrode and or more likely, the tiny contacts fail.
The limiter relay, in normal operation, never has to actuate. Contacts are like new.

 

[warriorpoet777]

I was the guilty one who put this question to you...

You were correct in all that you advised. The reed relays were covered in a thread many times but I didn't find the info on my own without asking around.

Maybe my search skills are not jedi level yet.

Solved that problem but of course I snapped off the stv 3 and 4 when I tilted the board to do the relays.

My local tech has done a few of these and has the stv 3 and 4 diy fabrication thread that echowars started prior to 2007.

I traded some extra reed relays for a pile of diodes and soldered and epoxy bonded the assembly to copper bases and installed.

Amp works, sounds good but the right channel still cuts out...

 

[markthefixer]

The STV-3h's are still available from Germany (eBay seller), the stv-4's are more problematic
but I do take in busted lead diodes, excavate and solder on new leads and stabilize the whole shebang with epoxy.
Even if replacements are found, I try to intercept EVERY STV-xh before it ends up in a garbage dump.

The thing is, and this is unappreciated: The STV-3h and VR1 (470 ohms) control the idle current
while
The stv-4h is a safety, that should the connection to the offboard STV-3h break, it limits the idle current
- but it does NOT control any idle current until that time as it's voltage is higher than the STV-3h and the VR can achieve.
Thus it should NOT be mounted off the board!!!


More detail needed, the 'negatives" as well as the positives:
like:
right channel cuts out BUT the protect relay is not dropping out.

My advice, pull Q8, Q9, Q10 & Q11 current limiters and test, see if the behavior is corrected. If so, we have a starting point. After that RL6 is next point of suspicion - disconnect it's contacts (not the coil).

 

[warriorpoet777]

I paid to have this amp "restored" by a local tech last summer.

There were a lot of quality caps installed and transistors replaced.

I will try to follow your advice finding and testing those components and likely will ask another local friend to help.

The nature of the cutting out has remained the same since the restoration.

From cold start the right channel is very low and dirty/distorted. When the volume is increased to near wide open the channel comes to life and functions properly at high volume.

If the amp is kept on the channel may still cut out but it's less and less frequent.

When taken to low volume it cuts out to low and distorted again until volume is again near wide open and then it comes back...

Thanks for the pointers, tell me where to send the stv's and they are yours.

James

 

[xlbee]

The nature of the cutting out has remained the same since the restoration.

From cold start the right channel is very low and dirty/distorted. When the volume is increased to near wide open the channel comes to life and functions properly at high volume.

If the amp is kept on the channel may still cut out but it's less and less frequent.

When taken to low volume it cuts out to low and distorted again until volume is again near wide open and then it comes back...

Sounds like the protection (speaker) relay. Try tapping the relay (with something non-conductive) to see if it has any effect on output when the issue is occurring.

 

[EastPoint]

Sounds like the protection (speaker) relay. Try tapping the relay (with something non-conductive) to see if it has any effect on output when the issue is occurring.

Agreed. A lot of repairpeople cheap out and don't replace the relays.

 

[markthefixer]

The nature of the cutting out has remained the same since the restoration.

From cold start the right channel is very low and dirty/distorted. When the volume is increased to near wide open the channel comes to life and functions properly at high volume.

If the amp is kept on the channel may still cut out but it's less and less frequent.

When taken to low volume it cuts out to low and distorted again until volume is again near wide open and then it comes back...

This appears to be a classic protection relay fault. Usually we say: "Replace it".

One COULD get abrasive on the contacts and get TEMPORARY relief, but we don't want to strip off the electroplated contact material.
You could try burnishing.

it IS a 24v coil, it's dimensions are : 36x32x45mm

edit: ( 653-MJN2CE-DC24 is (36mm x 39mm x 49(++)mm))

The chassis mounted relay is the speaker protection relay. I've not found a drop-in replacement. The Omron MJN relays are similar, but would require some rework on the chassis to mount them. Something like the MJN2CE-DC24. But the stock relay seems to be pretty reliable, even after all these years.

I suggest a test FIRST, temporarily put a shunt across the protect relay contacts for that channel and see if the problem clears up. If so, then we worry about cleaning or replacement.

Mouser has 653-MJN2CE-DC24 in stock, at 25 bucks...
there will be shenanagins to mount and fit it....

 

[warriorpoet777]

This appears to be a classic protection relay fault. Usually we say: "Replace it".



Mouser has 653-MJN2CE-DC24 in stock, at 25 bucks...
there will be shenanagins to mount and fit it....

Thank you!
I will try the shunt then clean and if resolved order the part cited.

 

[warriorpoet777]

Got the new main speaker relay and have the amp.open to install...

Why is there a diode across the a-b lead set on the original relay? Do I just put it on the new one?

 

[warriorpoet777]

?

This appears to be a classic protection relay fault. Usually we say: "Replace it".

One COULD get abrasive on the contacts and get TEMPORARY relief, but we don't want to strip off the electroplated contact material.
You could try burnishing.

it IS a 24v coil, it's dimensions are : 36x32x45mm

edit: ( 653-MJN2CE-DC24 is (36mm x 39mm x 49(++)mm))



I suggest a test FIRST, temporarily put a shunt across the protect relay contacts for that channel and see if the problem clears up. If so, then we worry about cleaning or replacement.

Mouser has 653-MJN2CE-DC24 in stock, at 25 bucks...
there will be shenanagins to mount and fit it....

 

[markthefixer]

Got the new main speaker relay and have the amp.open to install...

Why is there a diode across the a-b lead set on the original relay? Do I just put it on the new one?

Pioneer does that on their more expensive models.
Yes, put in a 1n4004 or such similar rectifier.

When the 1 watt magnetic field in the relay coil collapses because the relay coil current is interrupted, those lines of magnetic force are moving through the coils of the relay. This causes a negative voltage spike of considerable voltage to appear across the relay coil. This reverse voltage takes it's toll upon the relay driver transistor over time.
Putting in the diode stops the voltage from going larger than -0.6v - at a cost of a slightly slower relay release.

 

[markthefixer]

?

well, like I said, "shenanigans"....

I can't discern the relative sizes from that picture.

You could TRY to see if the new relay core (maybe with a bit of filing) can fit into the old case ....

 

[warriorpoet777]

Broke the diode lead off bit just put one I had laying around in same position and orientation and wired in the relay. Powered up and still no sound from right channel

Dad gum thing