| Sam Odom |
I did not find any help doing a "search" and I'm new to vintage tube stuff.
I picked up a Realistic SAF 24c integrated amp this week. It has four-6bm8, three-12ax7 and one-6ca4 EZ81 tubes. As for as I can tell only one of the 6bm8 is bad.
On the front plate it has for each side a tre and bass control (4 total). A single Vol control that has an inside and outside knob for adjusting balance. Also on the front at the top there are 3 (up & down) "on" "off" switches for "Preamp," "Tuner," & "Aux." Also on the front left is an up & down switch for "Phono" or "T.H."
In the rear: rca inputs for "Rec," "Aux," "Tuner," "T.H.," "X-Tal," and "Mag."
Here are my questions, any help is appreciated.
For what are the RCA inputs "Rec" - "T.H." - "X-Tal" used?
Why is there an on/off switch for the Preamp? (Preamp "on" has a better richer sound)
Explain the switch for "Phono" or "T.H."
Is this amp a 12watt (RMS) each channel, hence the "24c" in the name?
I better stop :-) I'm sure I'll have other questions later.
Thanks a bunch
Sam |
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| Bill Fitzpatrick |
| quote: |
For what are the RCA inputs "Rec" - "T.H." - "X-Tal" used?
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T.H. is tape head.
X-tal is for a crystal phono cart.
Boy, this thing is old. |
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| Sam Odom |
| quote: | Originally posted by Bill Fitzpatrick
T.H. is tape head.
X-tal is for a crystal phono cart.
Boy, this thing is old. |
Thanks, Bill.
So I guess the T.H. can be a useful preamp input also explains the front TH/Phono switch.
Another thing has me a bit puzzled. On the back is one "Speaker Phase" switch. It doesn't have any markings just click it to the left or right. Will this put both channels in or out of phase at the same time? Although I'm not sure which is which.
Sam |
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| Enzo |
I assume you are inside it, look at the wiring to that switch to see if it affects both sides. My guts says only one, so you can put them in phase if they are not. But who knows?
REC usually meant a line out for purpose of making recordings. It was a pre volume control signal from whatever input source was selected. See if that holds for your unit. It was for tape decks. The tape input, meaning the input from a tape deck is often called PLAY or PLAYBACK in contrast.
Tape Head is a high gain input like Phono, but it has a different EQ from the RIAA curve of the Phono. Tape head expects the signal directly from the tape head, as opposed to the TAPE input which expects a line out from the deck's channel amps.
Xtal - for crystal - is the same thing as CERAMIC on some amps. The output of a crystal phono cartridge is much stronger than the magnetic cartridge we are used to. They are used in cheap record players.
If you contact Tandy, there might even be schematics available. What is there to lose? |
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| planet10 |
| quote: | Originally posted by Sam Odom
Is this amp a 12watt (RMS) each channel, hence the "24c" in the name? |
probably more like 8 W, but 12 is what they could have speced it at. Pictures?Tandy never built any of their own, this is likely a Japanese OEM... i know some of the Monarch 6BM8 PP came with really nice iron. What brands of tubes?.
dave |
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| Tekko |
| Show us some pics of this amp please. |
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| planet10 |
| quote: | Originally posted by Sam Odom
The one 6CA4 and the three 12AX7 are "Realistic Lifetime" tubes. |
any little codes or "Made in X" labels -- sometimes they don't exist and if they do are often very hard to read -- those ones would likely get us a good idea of where the OEM was.
| quote: | | The 6BM8 are two different matched pairs and I'm not sure of either brand. The lettering is wore. I've contacted Gintaras Sakenas of KWtubes and am getting 4 new ones (I hope). |
I got some of the Russian equivalents from him... haven't tried them yet but did send a set of for cryo treatment.
dave |
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| Sam Odom |
| quote: | Originally posted by planet10
What brands of tubes?.
dave |
Hello Dave,
The one 6CA4 and the three 12AX7 are "Realistic Lifetime" tubes.
The 6BM8 are two different matched pairs and I'm not sure of either brand. The lettering is wore. I've contacted Gintaras Sakenas of KWtubes and am getting 4 new ones (I hope).
I will post pictures later.
Sam |
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| Tom Bavis |
| Sams Photofact folder 550-12 has the SAF24 - probably earlier than yours (no "c") I don't have that one, but they're not hard to find - infotronix.us and findatube.com are online sources. |
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| Sam Odom |
| The 6CA4 appears to be brand new but must be at least 30+ years old. Besides the "Realistic Lifetime" it has "Britain" in the same yellow lettering. Also has gold pins. |
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| Sam Odom |
Found a used 6bm8 today for $3.50... Now I have Stereo. Too early to tell but the MM input is nice. I'm using my 1979 Pioneer PL-560 to spin a few...
Here are a few Pics. The front. |
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| Sam Odom |
| Tomorrow, I'm going to look underneath at the caps/res and such. If everything is original, and I suspect it is, future plans will be to re-cap. The caps have to be dry. |
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| planet10 |
Looks very much like a Japanese build... the iron looks real nice...
dave |
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| planet10 |
Ia the chassis aluminum or steel/
dave |
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| Sam Odom |
| quote: | Originally posted by planet10
Ia the chassis aluminum or steel/
dave |
Steel...
Enzo was dead on, the T.H. input gain on the 24c is substantial. My Realistic SCT-22 Cassette Deck has a nice gain control and I had to turn it way down from the regular setting while playing (playing now) Bonnie Raitt's "Luck of the Draw" XDR tape. |
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| Sam Odom |
Thanks for the help, guys! One more question.
Speakers connection. There are 5 tabs for each side.
Far left tab is "common" next is "4ohm" then "8ohm" then "16ohm" the the last 5th one has no markings. What is it used for if anything?
I think I figured out the "Preout" on/off switch on the Front panel. It has to be "on" using T.H. or Phono but can be "off" with Tuner or Aux. When "off" the preout 12AX7 are bypassed.
Sam |
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| planet10 |
| quote: | Originally posted by Sam Odom
Far left tab is "common" next is "4ohm" then "8ohm" then "16ohm" the the last 5th one has no markings. What is it used for if anything? |
On Dyanacos tha position is used for connecting a derived centre channel speaker. on yours, i don't know...
dave |
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| Sam Odom |
| Bottom Plate "Japan" |
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| planet10 |
| quote: | Originally posted by Sam Odom
Under Amp |
Yep, Japanese build. What do you plan for this amp... keep it stock or soup it up? Do you need phono? Is just a power-amp enuff? Need tone-controls? Loudness?
I ask because removing any extraneous bits will let you clean it up even more.
dave |
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| planet10 |
| quote: | Originally posted by Sam Odom
Bottom Plate "Japan" |
Caught this after my earlier post... the 7 probably means 1967. |
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| Sam Odom |
| quote: | Originally posted by planet10
Yep, Japanese build. What do you plan for this amp... keep it stock or soup it up? Do you need phono? Is just a power-amp enuff? Need tone-controls? Loudness?
I ask because removing any extraneous bits will let you clean it up even more.
dave |
Not sure, Dave. I want to run it integrated with a tube am/fm tuner and phono with a pair of "the big fun box" speakers http://www.tnt-audio.com/clinica/bfb_e.html
Next big step is to re-cap it from there I'm not sure.
Sam |
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| planet10 |
| quote: | Originally posted by Sam Odom
Not sure, Dave. I want to run it integrated with a tube am/fm tuner and phono with a pair of "the big fun box" speakers |
It wouldn't hurt to start by tracing the circuit (and maybe losing the tone controls at the same time).
In the real world you can get away with 2 dual triodes for the phono section (my buddy uses the RCA circuit with 2 12AX7s and it works pretty well. You may not need a line level stage at all once the tone controls are removed.
dave |
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| Sam Odom |
Received 3 new JJ Tesla ECC83s from eBay Thursday. Replaced the 3 original 12ax7. Very NICE :D
Deeper soundstage because these tubes create a more forward sound without losing the backend. Highs are better too.
I hope the Russian 6BM8 when I get them have as much impact. |
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| Sam Odom |
| quote: | Originally posted by Sam Odom
I've contacted Gintaras Sakenas of KWtubes and am getting 4 new ones (I hope).
Sam |
Got the 4 Russian equivalent to the 6BM8 from Gintaras today. For the 1st 2 hrs or so of use the balance was off center to the right but now after about 4 hrs the balance has centered. Strange to me :eek: but I'm new to tubes...
How many hours of burn-in time will it take to hear the 'real' sound?
Sam |
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| LooseChange |
Hi,
Sorry to bring up such an old thread but it's the ONLY hit I got for this amp!!
I've got one and I am looking for the Schematic or owners manual or anything to help me go through the amp to restore it.
Thanks!
I build Guitar amps for fun....
www.loosechange.freeservers.com |
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| kevinkr |
Old thread...
I am currently restoring a 1960 vintage Stereodyne 80 like the one my dad used to have. This one eats modern 6BQ5 for breakfast. It's rated 20Wrms per channel and will actually produce that much power on the bench.
I would not run it much before at least replacing the main filter caps - modern JJs should fit nicely. (They did in the Stereodyne amp) Also the coupling caps to the output tube grids as the very minimum. The ones used by the Japanese OEM get very leaky with age.
Service manuals for this gear show up from time to time on eBay at very reasonable prices. |
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| LooseChange |
I decided to work backwards and hash out the circuit. In my search I came up with a "generic" schematic that was almost exactly like the 24C. I put the differences in red.
The Schematic is just one channel and starts at the AUX input. There is a preamp in front of that to power weak signals like a mag phono.
Tell me what you think.
Thanks! |
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| bob31411 |
Hi,
I am new to the forum and I know this is a really old thread. I have recently acquired a Realistic SAF-24D stereo amplifier. I was wondering if anyone has an owner's manual (good copy would be fine) or a service manual. The unit is functioning, but just wanted to find out a little more about it. There is very very little on the net regarding this amp. Thanks. Bobby |
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