new question:
sound depreciated in level on 5F1 SE 6v6gt guitar amp diy build kit.
reason: electric bass played thru 5F1 into 1960 alnico sanyo 3way (12"6",3", all paper, all 8ohms, all 25rms, all alnico, all made japan). spkrs in series excepting 3" who rides parallel onto 6" but is locally protected by bipolar cap.
i tested 5y3 rectifier on b&k707, gets real hot to hand, but tests good at 88 reading whatever thats suppose to mean. its the hotness that scares me.
5F1 still plays just a tad down in level, but it resulted after taking a break (deenergized complete), then resumption revealed the softer volume, and all musicians unanimously agreed. sound tried to return to same bigger level rotating the preamp knob homed always at lunch, so i caig'd it, as the cackle sound did seem to repeat itself exactly at 12 o'clock. the 12ax7b and 6v6gt test brand new, and are shuguang.
should i purchase another 5y3 to chk if it too heats excessively in the b&k707?
sound depreciated in level on 5F1 SE 6v6gt guitar amp diy build kit.
reason: electric bass played thru 5F1 into 1960 alnico sanyo 3way (12"6",3", all paper, all 8ohms, all 25rms, all alnico, all made japan). spkrs in series excepting 3" who rides parallel onto 6" but is locally protected by bipolar cap.
i tested 5y3 rectifier on b&k707, gets real hot to hand, but tests good at 88 reading whatever thats suppose to mean. its the hotness that scares me.
5F1 still plays just a tad down in level, but it resulted after taking a break (deenergized complete), then resumption revealed the softer volume, and all musicians unanimously agreed. sound tried to return to same bigger level rotating the preamp knob homed always at lunch, so i caig'd it, as the cackle sound did seem to repeat itself exactly at 12 o'clock. the 12ax7b and 6v6gt test brand new, and are shuguang.
should i purchase another 5y3 to chk if it too heats excessively in the b&k707?
Hi hewo,
Shouldn't as they are hermetically sealed at the factory. There is a wear out mechanism in semiconductors, but they need to be running or stored at elevated temperatures. Getting them too cold can cause things to crack. But they are comfortable as long as you are.
Antenna types will not cause problems in the output circuit!!!
Sometimes people want things they can't have. You can either replace the antenna, replace the coax cable, or he will be able to find the splice. What you can do is fix the inner conductor, wrap in foam, fix the shield, then seal it and cover with black heat shrink tubing. That is about the best anyone can do. You will have an impedance discontinuity at the splice, nothing can be done about that.
-Chris
Shouldn't as they are hermetically sealed at the factory. There is a wear out mechanism in semiconductors, but they need to be running or stored at elevated temperatures. Getting them too cold can cause things to crack. But they are comfortable as long as you are.
Antenna types will not cause problems in the output circuit!!!
Please use your caps keys where needed.
Sometimes people want things they can't have. You can either replace the antenna, replace the coax cable, or he will be able to find the splice. What you can do is fix the inner conductor, wrap in foam, fix the shield, then seal it and cover with black heat shrink tubing. That is about the best anyone can do. You will have an impedance discontinuity at the splice, nothing can be done about that.
-Chris
thanks for splice how-to
and will purchase explicitly labeled germ "made japan", new, then examine for leakiness if any, as prior ressurrected same radios not leaky, repaired using "japan" yet still had precisely 1vdc steady onto eight ohm voicecoil (no harm).
so lost money over ecg121 sylvania five germ purchases ebay, all nos, but not "japan"
and will purchase explicitly labeled germ "made japan", new, then examine for leakiness if any, as prior ressurrected same radios not leaky, repaired using "japan" yet still had precisely 1vdc steady onto eight ohm voicecoil (no harm).
so lost money over ecg121 sylvania five germ purchases ebay, all nos, but not "japan"
Hi hewo,
I've been asked to repair antennas as well. You got my stock answer, except that I used to include service pricing too.
I didn't sign up to be a coax repair guy just to hear complaints afterwards as well.
Some leakage is perfectly normal. If you measured no leakage, check the E-B voltage drop as I bet those are silicon (= won't work well). Ge transistors have high gain coupled with high leakage. Can you guess why the industry moved to silicon parts? The move created the need for another transistor, but at least they didn't go bang in a the hot summer weather.
Any "real" number stamped as coming from the correct country should be fine. For Japanese parts I would expect to see the 2Sx numbering system. GM (Delco) used to have parts made in Mexico, so that is probably a real part with the DS series numbered part.
I am wishing you luck with this. You learned some lessons the hard way. You will remember this 'till you end your days, sorry.
-Chris
I've been asked to repair antennas as well. You got my stock answer, except that I used to include service pricing too.
I didn't sign up to be a coax repair guy just to hear complaints afterwards as well.Some leakage is perfectly normal. If you measured no leakage, check the E-B voltage drop as I bet those are silicon (= won't work well). Ge transistors have high gain coupled with high leakage. Can you guess why the industry moved to silicon parts? The move created the need for another transistor, but at least they didn't go bang in a the hot summer weather.
Any "real" number stamped as coming from the correct country should be fine. For Japanese parts I would expect to see the 2Sx numbering system. GM (Delco) used to have parts made in Mexico, so that is probably a real part with the DS series numbered part.
I am wishing you luck with this. You learned some lessons the hard way. You will remember this 'till you end your days, sorry.
-Chris
Ok will purchase japan stamped Sylvania ecg121, avoid general electric sk germ equivalent.
Splice upgrade to be kept "tiny" as do'able from a pathlength standpoint, assuring foam center conductor insulation, and copper foil envelope shield contiguity to existent braided shield, concentricity is key, of splice, geometrically.
Splice upgrade to be kept "tiny" as do'able from a pathlength standpoint, assuring foam center conductor insulation, and copper foil envelope shield contiguity to existent braided shield, concentricity is key, of splice, geometrically.
Hi hewo,
Actually, the GE and RCA lines were pretty good normally. ECG (Sylvania) is highly questionable no matter where they are made. ECG/NTE is complete junk.
-Chris
Actually, the GE and RCA lines were pretty good normally. ECG (Sylvania) is highly questionable no matter where they are made. ECG/NTE is complete junk.
-Chris
Hi hewo,
Those should work fine.
If you are shopping for equivalent parts, never look for the substitute number, always the original number. You can't "cross in and cross out!".
-Chris
Those should work fine.
If you are shopping for equivalent parts, never look for the substitute number, always the original number. You can't "cross in and cross out!".
-Chris
camaro radio 91APB1 awaiting germanium
Three radio freq and two audio upstrm ds503 bad, awaiting ecg126 trio already replaced audio ecg123ap
Refunded on seven replacement ds503, called ecg121 and rca sk3006, and ds503, all brand new but gross lkg > 5ma at <2dcv applied by b&k tester
So gonna keep searching for mystery Sylvania ecg121 that absolutely zero lkg, because prior radio successful with it, why, must be particular era it was made, batch
Qinpu not investigated since last post, but we know rail one side not alive on ic pin delivery of it, and one 9.1zener lacks yield this differential.
Aside, repaired retirees touch lamp elex, module swap, four dollars freeship communist china, his wife so happy reading newspapers magazine s daily usage. Module will fatigue ten years life expectancy why, scr not heatsinked
Aside bridged 1meg metalfilm resistor across 1meg master vol pot acting as the 224 resistor schematic 5f1, forum warned 1meg pot here is not healthy feeding signal 6v6gt input
Gotta upload 5f1 later, can't now, stndby
Three radio freq and two audio upstrm ds503 bad, awaiting ecg126 trio already replaced audio ecg123ap
Refunded on seven replacement ds503, called ecg121 and rca sk3006, and ds503, all brand new but gross lkg > 5ma at <2dcv applied by b&k tester
So gonna keep searching for mystery Sylvania ecg121 that absolutely zero lkg, because prior radio successful with it, why, must be particular era it was made, batch
Qinpu not investigated since last post, but we know rail one side not alive on ic pin delivery of it, and one 9.1zener lacks yield this differential.
Aside, repaired retirees touch lamp elex, module swap, four dollars freeship communist china, his wife so happy reading newspapers magazine s daily usage. Module will fatigue ten years life expectancy why, scr not heatsinked
Aside bridged 1meg metalfilm resistor across 1meg master vol pot acting as the 224 resistor schematic 5f1, forum warned 1meg pot here is not healthy feeding signal 6v6gt input
Gotta upload 5f1 later, can't now, stndby
Attachments
upload 5f1 blocked why
Finally got android to upload dunno why no response clicking browse for attachment earlier as if java unsupportable, reset browser settings, still blocked, so exit webmail, re enter, link forum, login, attemp post, weird behavior android.
So 1meg pot post 1st triode, 221 treble bypass, next triode output 1meg pot, bypassed 221 treble, tiedown schematic resistor 224 substituted w/ this master vol bridged w/ 1meg, so effectively 500k tiedown max value. The 221 styrene rolled caps thrill the pot adjustments esp affording their inductances (rolled).
I am wondering whether to either lower or bypass altogether the single guitar input now effectively 68k parallel 68k, or 33k, or would this overwhelm stage first input?
Or could intro opamp fet to receive raw guitar as buffer limiter, fed next to stage 1 stripped of 33k input temperament. Effectively fet opamp acts as pre-preamping permitting threshold oversaturation by ecc83 triode stage one. There's plenty ac to steal from pt to operate fet opamp and opamp mininscule physical congestion sized.
Finally got android to upload dunno why no response clicking browse for attachment earlier as if java unsupportable, reset browser settings, still blocked, so exit webmail, re enter, link forum, login, attemp post, weird behavior android.
So 1meg pot post 1st triode, 221 treble bypass, next triode output 1meg pot, bypassed 221 treble, tiedown schematic resistor 224 substituted w/ this master vol bridged w/ 1meg, so effectively 500k tiedown max value. The 221 styrene rolled caps thrill the pot adjustments esp affording their inductances (rolled).
I am wondering whether to either lower or bypass altogether the single guitar input now effectively 68k parallel 68k, or 33k, or would this overwhelm stage first input?
Or could intro opamp fet to receive raw guitar as buffer limiter, fed next to stage 1 stripped of 33k input temperament. Effectively fet opamp acts as pre-preamping permitting threshold oversaturation by ecc83 triode stage one. There's plenty ac to steal from pt to operate fet opamp and opamp mininscule physical congestion sized.
Attachments
reverb weakened why
accidently soldered coaxial micro wiring from mobo to pan with pinouts reversed of both shake and listen ports. that means shake energy gets earthed and its drive fet angry. so replaced both 15 and 16 which drive pan springs. but when tested in tester both 15 & 16 appear okay. so why is reverb weakened? do the slugs lose permanency magnetism ? or are their alignments within core sagging with gravity acting and with tensioned carriage bowing? or is it circuitry?
accidently soldered coaxial micro wiring from mobo to pan with pinouts reversed of both shake and listen ports. that means shake energy gets earthed and its drive fet angry. so replaced both 15 and 16 which drive pan springs. but when tested in tester both 15 & 16 appear okay. so why is reverb weakened? do the slugs lose permanency magnetism ? or are their alignments within core sagging with gravity acting and with tensioned carriage bowing? or is it circuitry?
what's a nice pan to try?
impedance shaker?
impedance listener?
or just get any impedance ball parked for solidstate drive solidstate recovery?
which is what? 4K shake 8K listen ?
impedance shaker?
impedance listener?
or just get any impedance ball parked for solidstate drive solidstate recovery?
which is what? 4K shake 8K listen ?
Hi hewo,
These are mounted with a rubber "O-ring". If you screw it right down it may not work properly. They should be free to move. In case it got damaged, flip it over to have a look. The springs (normally two or three) should hook into one side and also the other. They will sag a little because the are - springs.
Take a picture of it mounted and another flipped over so we can see the inside.
Don't try to replace the mechanical unit with a solid state one. You're adding too many unknowns into the mix by doing that.
-Chris
No clue. Blocking programs and cookies is normally the cause.
I'm a little lost with the terminology. Mobo = main board I guess, pan = reverb box?
Over decades I guess it can happen. Not from what you just did though. You may not be giving the springs enough drive.
Now I am really lost. Why are you replacing the reverb box? Just whack it with your fingers to see if it works. You should hear something like a "bwang" sound. It is possible that you got it turned around, driving the wrong end. I don't know how robust the pickup coils are.
These are mounted with a rubber "O-ring". If you screw it right down it may not work properly. They should be free to move. In case it got damaged, flip it over to have a look. The springs (normally two or three) should hook into one side and also the other. They will sag a little because the are - springs.
Take a picture of it mounted and another flipped over so we can see the inside.
Don't try to replace the mechanical unit with a solid state one. You're adding too many unknowns into the mix by doing that.
-Chris
Yes your translations are accurate of my writings.
Funny, the 15&16 j112 fets removed tested junk out of circuit but retesting later appear ok, meaning fet injury recovery? Hard to believe. Flaky? Recall had pinouts reversed so fet driving into pure earth would it become permanently injured doing so? Look there's a 3k3 cushion before hitting earth.
Gotta unstick pans lip flange off from the chassis internal flooring, window weatherstrip for cushioning used here tiny drop contact cement.
Micro coaxial purchased from military surplus, extremely fine, center conductor is gauge 32 stranded insulated by kapton fireproof then silvered shield braided, then white asbestos weave jacket fireproof. Asbestos difficult trimming back, or is this white woven jacket fiberglass fireproof?
Will get photos
Pan stamped ports "input" and "output", output ALWAYS high impedance, why, because sensitive listening device always high impedance. Pan marsh penned 40 ohm dc and 80 ohm dc
Funny, the 15&16 j112 fets removed tested junk out of circuit but retesting later appear ok, meaning fet injury recovery? Hard to believe. Flaky? Recall had pinouts reversed so fet driving into pure earth would it become permanently injured doing so? Look there's a 3k3 cushion before hitting earth.
Gotta unstick pans lip flange off from the chassis internal flooring, window weatherstrip for cushioning used here tiny drop contact cement.
Micro coaxial purchased from military surplus, extremely fine, center conductor is gauge 32 stranded insulated by kapton fireproof then silvered shield braided, then white asbestos weave jacket fireproof. Asbestos difficult trimming back, or is this white woven jacket fiberglass fireproof?
Will get photos
Pan stamped ports "input" and "output", output ALWAYS high impedance, why, because sensitive listening device always high impedance. Pan marsh penned 40 ohm dc and 80 ohm dc
Hi hewo,
When silicon is damaged, that's a one way street. They never come back. It is very possible to degrade solid state devices with the outright failure happening in the future, years maybe. You may have had a bad connection while testing them the first time, or the pinout was wrong.
Standard shielded wire is best. For the driven side you probably want a heavier conductor. Never get fancy when you rewire. The "great" wires may only be great for a different application. Anyway, that might be your problem. Please connect the reverb unit with an original type of wire - if not the wires that came out. The driven side does not require shielded cable to begin with.
Please call the reverb unit by it's proper name. They may also be known as a reverb spring unit. Pan makes no sense to anyone but you.
I think putting the correct wire back into the amp will fix the reverb problem.
-Chris
When silicon is damaged, that's a one way street. They never come back. It is very possible to degrade solid state devices with the outright failure happening in the future, years maybe. You may have had a bad connection while testing them the first time, or the pinout was wrong.
Standard shielded wire is best. For the driven side you probably want a heavier conductor. Never get fancy when you rewire. The "great" wires may only be great for a different application. Anyway, that might be your problem. Please connect the reverb unit with an original type of wire - if not the wires that came out. The driven side does not require shielded cable to begin with.
Please call the reverb unit by it's proper name. They may also be known as a reverb spring unit. Pan makes no sense to anyone but you.
I think putting the correct wire back into the amp will fix the reverb problem.
-Chris
reverb tank coaxial connections
Tank mount orig was cab basement but I changed tank location to chassis floor internal so coaxials shortened length substantially shorter 33% now length.
I can revert coaxial wires to factory thick ones yard lengths each.
But 1st let me scope the drive signal and the returned signal magnitudes, should roughly be around 1 to 2 vac signal at nominal settings dials, channel clean and channel dirty.
I don't think 12" coaxial runs are choking signal transport, even at 32 wire size stranded of signal conductor.
Look at that tantalum 105x35vdc onto fet15 rail drive, maybe culprit?
Tank mount orig was cab basement but I changed tank location to chassis floor internal so coaxials shortened length substantially shorter 33% now length.
I can revert coaxial wires to factory thick ones yard lengths each.
But 1st let me scope the drive signal and the returned signal magnitudes, should roughly be around 1 to 2 vac signal at nominal settings dials, channel clean and channel dirty.
I don't think 12" coaxial runs are choking signal transport, even at 32 wire size stranded of signal conductor.
Look at that tantalum 105x35vdc onto fet15 rail drive, maybe culprit?
reverb tank drive coaxial wire
Tank input, or drive, does not connect braided shield to tank metal, only the tank output or recovery does. So the rca connection of input is isolated tank metal, yet, back on mobo both coaxial braided shields are contiguous earth landings, so same potential. This is to avoid looping earth, as the drive energy is significant enabling spring agitation by the driven coil fed this energy. Driving springs is much more inefficient than listening to the springs on the recovery side coil.
Tank input, or drive, does not connect braided shield to tank metal, only the tank output or recovery does. So the rca connection of input is isolated tank metal, yet, back on mobo both coaxial braided shields are contiguous earth landings, so same potential. This is to avoid looping earth, as the drive energy is significant enabling spring agitation by the driven coil fed this energy. Driving springs is much more inefficient than listening to the springs on the recovery side coil.
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