61 01 21 CG preamp repair

[TC Chris]

Greg, if you turn them all on at once you could heat the shop in the winter.

Bill

You sometimes need heat in AZ, right?

I imagine they start looking at the thermostat when the temp drops below 75....

Chris Campbell

[electra225]

The car thermometer said 58 degrees on my drive home this evening. I ran the heater all the way home. Not set on max heat, mind you, but on maybe a little over half way. It felt good, too. We have covered the flowers and cucumbers the last two nights and will again tonight to prevent them getting nipped with frost. Supposed to be 75 tomorrow. That is just fine with me.

A Concert Grand uses about 360 watts lighting the tube filaments. The Stereo Theater somewhere around 300 IIRC. Those two would make a pretty good electric heater.

[Hydrolastic]

Hello Guy's first tool has arrived! A Fluke 77 IV Off eBay about 150 with shipping. Pretty happy with condition and it seems to work. I want to get some of those clamping leads for it. If anyone has a recommendation on type or size let me know. Also what is the next tool I will need? soldering iron? and vacuum solder sucker tool? My dad used to have a set of the nut drivers but I dont remember the brand. Hydro

[electra225]

You've established a baseline so you are okay there. You have a meter. You need a schematic and some desoldering braid. Document your work, take pictures, make notes so if you have an issue, you can go back over your work. Ask if you get stuck. We are here to help. You'll do fine. Good luck, Hydro.

[William]

Hydro. You will need a soldering station, one similar to this:

https://www.amazon.com/Weller-WLC100-40 ... B000AS28UC

What Greg was referring to with de-soldering braid is something like this:

https://www.amazon.com/NTE-Electronics- ... C83&sr=1-5

Here's the solder sucker I have, and I do not like it. It does not work all that well. Maybe others on the forum have a better recommendation:

https://www.amazon.com/Engineer-Aluminu ... 93&sr=1-29

The soldering station in the link I provided is the one I purchased, and it works well. I'm jealous as I paid the higher price. The de-soldering tape/braid is the brand I use and it too works well. One member on the forum has a vacuum de-soldering device and he really likes it.

I hope this helps, and yes, you still need a schematic before you start. I hope to have you for you this weekend.

Bill

[Ken Doyle]

Here's the solder sucker I have, and I do not like it. It does not work all that well. Maybe others on the forum have a better recommendation:

https://www.amazon.com/Engineer-Aluminu ... 93&sr=1-29

Bill

EDSYN DS017 The Original Deluxe Solder Sucker SOLDAPULLT

https://www.amazon.com/EDSYN-The-Origin ... B006GOKVKI

[William]

Thanks, Ken!

Bill

[Hydrolastic]

Thanks a lot you guys. It's going be slow as I still have to order and get this stuff. Too bad there is no radio shack or anything like it that I know of around here. Friend of mine offered me a signal generator not sure what it does, what is it worth? 50 dollars? I will look at the soldering station first.
BTW I measured a couple of speakers for impedance and it worked great. Now I want to measure other stuff ! Hydro

[electra225]

A signal generator is an essential piece of test equipment if you intend to stay in the electronics repair hobby. I don't believe you need one for what you are doing here. And I wouldn't give $50 for one unless I knew it would do what I needed it to do and had some idea of its operating condition. Old test equipment is like old stereos. Most of the time, they need refurbishment if they haven't already been done. Test leads can be spendy, so you should consider that cost if the one you are looking at isn't so equipped. I personally like Heathkit equipment, since it is plentiful, reasonably priced and easily repaired.

[TC Chris]

For desoldering, I have an old Radio Shack device--an electric soldering iron with a hollow tip, and a rubber bulb connected to the tip via a tube. It melts the solder and then you squeeze release the bulb to suck it up. It works pretty well. RS is long gone but there's a device that's similar in function here:

https://www.showmecables.com/desolderin ... bsQAvD_BwE

Chris Campbell

[William]

Hydro, check your email and see if you can open what I sent you. I'm hoping it works this time.

Bill

[Hydrolastic]

Hello William, Thank you that worked perfectly. Much more clear than the 54 series Sams I purchased. It has the Am and Fm alignment and the 61 series schematics Thank you again. Hydro

[William]

My pleasure, I'm glad it finally worked.

Bill

[electra225]

Hydro, how are you doing on your Concert Grand restoration project? We haven't heard in awhile and inquiring minds want to know.....

[Hydrolastic]

Hello, I am not working on it yet! This month has been crazy as I have started on the prep work for the June plumbing work. Not looking fwd to the concrete work at the end. lots of details to take care of. It will be after Labor Day at least before I get back onto the stereo's. I have been listening to the CG and the other day I had to turn up "ride my seesaw" to 9. Holy cow that song and CG were made for each other. The Stereorama out in the garage just quit. Would not turn on. Thanks for bringing it up I do want to get a soldering station. Hydro

[William]

Hydro, do you still have the two Imperial cabinets? Did you decide what you were going to do with your Imperial?

Bill

[Hydrolastic]

Hello William, At first when you asked about the imperial, the thought was nothing going on. but a bit ago I purchased a extra 182 ba amp for the continental. This amp was also used in the imperial. It came with a 54 03 amp and even though its not identical with the 61 series that originally came in the imperial it will look very close. The imperial is also a closed speaker unit so I am hoping it would sound almost as good as the CG but just a single lower powered stereo amp. The damaged imperial had the speakers, record changer, 61 series preamp all the trim but neither had the speaker cabinet backs so new ones would have to be made for that. It would be perfect high fidelity tube sound for the garage. However all of this has to wait for the home improvement projects to be further along. Got to go, lots to do!

[Hydrolastic]

Hello Guys, life with the CG has been great. Still am impressed with its sound. I had received a part from Ebay the gold swing arm for the record changer. I installed it and it works. I then went through the process for plugging it into the system. I turned on the phono and tried it out. It plays at 33 rpm but very slowly. Thing is the the magic eye tube turned on and so did the light for the dial. So that part only works on the phono switch. I love this thing it truly sounds great. But I am realizing that there are things I would like to do. I would like a bare bones unit. where only the minimum stuff its running while in Tape /bluetooth mode.
I never turn on the remote system. There is no battery in the hand controller I don't think it has ever had one. Also I never turn on the FM on either FM or MPX I want to just unplug the MPX unit. I can't yet though I will get to that later. The FM did play some stations so it is working its clearly not very good fidelity like when its playing the bluetooth system and I could hear the difference with the mpx in stereo. On Am, I heard stations but not well. Could be antenna but listening to it I think it internal
I would like to get the record player going again. Even though it was playing slowly I could hear the Stereo. I would like the dial light to be on. I am not so sure about the magic eye though. Its not on when its in the tape position. At least it wasn't when I went back to try it. It's very intermittent and dim.
Only on Tape/ bluetooth does it play like a CG should every other knob position it sound poor. so I think the amps are in great shape. Its the preamp that needs the work. just a report no need to reply. Hydro

[TC Chris]

The slow play on the record changer is likely from motor bearings that need cleaning or lube. Me, I tend to add oil but others prefer to soak in solvent first to get the old stuff out. If the motor has been serviced and also the bearings for the turntable, then maybe your idler wheel is glazed. A quick fix is to remove it, mount it temporarily on an axle like a nail or rod of suitable diameter, and hold the face of the rubber against a rotating sandpaper cylinder or disc. The wheel will spin and the glazed surface will abrade.

Usually if it's the idler wheel, the speed will be irregular, not steadily slow.

Chris Campbell

[Hi-Fi-Mogul]

Those Collaro motors are known to gum up after
all those years.

Best approach is to do a dis-assemble and
thorough cleaning of bearing housings and
those oil reservoir pads.

Solvent soaking is a long lasting assist.

Then it'll run for years.