Heathkit TA-16

[DBK]

i just scored this amp recently from a Craigslist deal. it works well enough the tremolo isnt working but every thing else does.

I have the schematic and for right now it does me no good. I'm not that advanced. but i was wondering if anyone could point me to a place to get the actual manual. in a .pdf or something virtual.. i would greatly appreciate it. any advice on what to upgrade or mod would be greatly appreciated as well.

Thanks.

[Jazz P Bass]

Vintage Manuals has one.
$24.00
Link: ta-16 Manuals from Vintage Manuals, Inc.

[juice]

There is one available for free here:
http://harmony.demont.net/documents/...t_TA_16_01.gif

By the way, I love this amp a lot, and it's been my main amp for about two years now.

This amp coupled with my teisco with gold foil pickups cranked to 10 is quite possibly one of the best raunchy overdrive sounds (a la white stripes) you can get for ANY amp, tube included.

Unfortunately I'm moving into a shared house in San Francisco (which means there's all sorts of neighbors and roommates to piss off) so I need something much quieter, and this amp sounds best past 6.

[Mark Hammer]

I just picked one up yesterday in decent working order for $80 from a local Kijiji ad. A good friend built one during high school, so many years ago, and I coveted it then. Now I have one. The tremolo isn't working on this one either, but I assume it is simply a matter of bulb replacement.

One thread or blog I stumbled onto yesterday, in search of a schematic, indicated that he improved the noise specs on his by replacing the 2N3391 at the input stage with a 2N5088. Once I can get the damn amp chassis out of the cabinet to work on, I'll see if a 2N5089 helps even more. A bit of residual hum also suggests the power supply caps are past their shelf life. Finally, the wire to the speakers could stand something thicker in its place, and while it works fine the reverb connector cable is a little on the stiff and almost-crunchy side.

Other plans for mine include:
- cleaning up the pots and applying some Stabilant to them
- a tremolo speed indicator LED (goes between R61 and Q12; cathode goes to collector of Q12)
- tone shaping of the reverb (vary value of C25)
- bright switch for volume on each channel (I'll start out with .01uf and adjust from there)
- selectable turnover frequency for tone controls (toggle for C101/102 and C4/C11)
- a proper power cable

Do any of you have any idea what speakers were used on these? They're 12" with a 1" voice coil, and a square ceramic magnet that looks to be about 8-12oz. The numerical information printed on the back of the magnet (besides 8 ohms) is
401 - 117
137 7119

The cones have "426 25" printed on the back.

Going by this page - Vintage Guitars Info - dating vintage guitars, amps by date source code - it is possible they are CTS (137) speakers made in the 19th week of 1971. That assumes, of course, that the second line is the source code and not the first one. Since I haven't found a source code for "401" yet, and CTS seems like a reasonable source for an OEM speaker, I'm figuring they are CTS.

[Mark Hammer]

Have to spend a lot of time cleaning this thing up, but I replaced the 2N3391 input transisitors with 2N5089 on both channels this evening, and the unit is blissfully hiss-free. It makes the hum more obvious but I guess one victory at a time, eh? Next come the 100uf supply caps.

I also stuck a .01uf cap across the input and wiper lugs of the volume pot on the normal channel and there is an audible difference. It may take a value as high as .015-.022uf to produce a change in treble response as obvious as in the case of the Fender Bright switch, but the good news is that at least .01uf works.

Some STP Son of a Gun car vinyl protectant, a stiff bristle brush, and some paper towels, and I was able to bring some character back to the tolex. The "grill cloth" on this one was nylon screen material. I'm going to replace it with Boogie-style cane material I bought from Lee Valley Tools. Need to figure out a viable strategy for mounting it. Finally, there is no back plate behind the amp section, so I'll see what I can do about fabricating one.

[guitarle]

Credence speaker mfg. code is 401

I just picked one up yesterday in decent working order for $80 from a local Kijiji ad. A good friend built one during high school, so many years ago, and I coveted it then. Now I have one. The tremolo isn't working on this one either, but I assume it is simply a matter of bulb replacement.

One thread or blog I stumbled onto yesterday, in search of a schematic, indicated that he improved the noise specs on his by replacing the 2N3391 at the input stage with a 2N5088. Once I can get the damn amp chassis out of the cabinet to work on, I'll see if a 2N5089 helps even more. A bit of residual hum also suggests the power supply caps are past their shelf life. Finally, the wire to the speakers could stand something thicker in its place, and while it works fine the reverb connector cable is a little on the stiff and almost-crunchy side.

Other plans for mine include:
- cleaning up the pots and applying some Stabilant to them
- a tremolo speed indicator LED (goes between R61 and Q12; cathode goes to collector of Q12)
- tone shaping of the reverb (vary value of C25)
- bright switch for volume on each channel (I'll start out with .01uf and adjust from there)
- selectable turnover frequency for tone controls (toggle for C101/102 and C4/C11)
- a proper power cable

Do any of you have any idea what speakers were used on these? They're 12" with a 1" voice coil, and a square ceramic magnet that looks to be about 8-12oz. The numerical information printed on the back of the magnet (besides 8 ohms) is
401 - 117
137 7119

The cones have "426 25" printed on the back.

Going by this page - Vintage Guitars Info - dating vintage guitars, amps by date source code - it is possible they are CTS (137) speakers made in the 19th week of 1971. That assumes, of course, that the second line is the source code and not the first one. Since I haven't found a source code for "401" yet, and CTS seems like a reasonable source for an OEM speaker, I'm figuring they are CTS.

Credence 117 is a speaker code I found at Weber VST Speaker codes and applications. It seems they may have taken over production for Heathkit in the 70's. I have a TA-16 which appears to be made around 1979. It is the same as my 1968 but has the Credence speakers instead of C12Rs and carbon film resistors instead of carbon comp.

[bware]

LED?

I just picked one up yesterday in decent working order for $80 from a local Kijiji ad. A good friend built one during high school, so many years ago, and I coveted it then. Now I have one. The tremolo isn't working on this one either, but I assume it is simply a matter of bulb replacement.

One thread or blog I stumbled onto yesterday, in search of a schematic, indicated that he improved the noise specs on his by replacing the 2N3391 at the input stage with a 2N5088. Once I can get the damn amp chassis out of the cabinet to work on, I'll see if a 2N5089 helps even more. A bit of residual hum also suggests the power supply caps are past their shelf life. Finally, the wire to the speakers could stand something thicker in its place, and while it works fine the reverb connector cable is a little on the stiff and almost-crunchy side.

Other plans for mine include:
- cleaning up the pots and applying some Stabilant to them
- a tremolo speed indicator LED (goes between R61 and Q12; cathode goes to collector of Q12)
- tone shaping of the reverb (vary value of C25)
- bright switch for volume on each channel (I'll start out with .01uf and adjust from there)
- selectable turnover frequency for tone controls (toggle for C101/102 and C4/C11)
- a proper power cable

Do any of you have any idea what speakers were used on these? They're 12" with a 1" voice coil, and a square ceramic magnet that looks to be about 8-12oz. The numerical information printed on the back of the magnet (besides 8 ohms) is
401 - 117
137 7119

The cones have "426 25" printed on the back.

Going by this page - Vintage Guitars Info - dating vintage guitars, amps by date source code - it is possible they are CTS (137) speakers made in the 19th week of 1971. That assumes, of course, that the second line is the source code and not the first one. Since I haven't found a source code for "401" yet, and CTS seems like a reasonable source for an OEM speaker, I'm figuring they are CTS.

I can't help you with the speaker question. The amp I obtained has 1973 Realistic (Utah) speakers. I do want to try the transistor switch. What LED is appropriate for the Tremolo indicator?

[Glen F]

Have to spend a lot of time cleaning this thing up, but I replaced the 2N3391 input transisitors with 2N5089 on both channels this evening, and the unit is blissfully hiss-free. It makes the hum more obvious but I guess one victory at a time, eh? Next come the 100uf supply caps.

I also stuck a .01uf cap across the input and wiper lugs of the volume pot on the normal channel and there is an audible difference. It may take a value as high as .015-.022uf to produce a change in treble response as obvious as in the case of the Fender Bright switch, but the good news is that at least .01uf works.

Some STP Son of a Gun car vinyl protectant, a stiff bristle brush, and some paper towels, and I was able to bring some character back to the tolex. The "grill cloth" on this one was nylon screen material. I'm going to replace it with Boogie-style cane material I bought from Lee Valley Tools. Need to figure out a viable strategy for mounting it. Finally, there is no back plate behind the amp section, so I'll see what I can do about fabricating one.

My Dad built this amp for me when I was 10. At 51, I'm just getting back into playing again. Did you ever manage to get rid of the hum?

[danfrank]

Hi. I am new to this forum and would like to share what I have done with my Heathkit TA-16. A friend gave it to me 20 years ago as he was going to medical school. The only thing it did well was shock the heck out of whoever was playing it. So I did some work to it. Now it doesn't shock the player anymore. Still has tremolo, reverb and 40-50 watts of output power.



What do ya think?

[Enzo]

Hi, welcome. Three wire power cord is a must.

I still have one of those in my shop. I know I will never get to rebuilding it now. Works, but needs various issues solved.

[danfrank]

Thanks.
Yes, I installed a 3 wire cord and took out the death cap.

Ha ha... I guess I'm fishing for ooo's and aah's. Take a look at the picture of the amp. It may look like a TA-16 amp on the outside but look at the guts... Vacuum tubes! I cloned a Fender Pro and used the TA-16 for the chassis and cabinet.

[Enzo]

You know, I looked right at that, and it never dawned on me what I was seeing. Duh.

[Bruce Roberts]

Hi Dan,
I have a TA 16 and I like your mod! Do you have any more of the PCB or can you share the layout files?
Thanks very much
Bruce