David Bogen HT-16

6/16/2007 2:09:52 PMTom

Hi, Does anyone out there have a schematic for a David HT-16 phonograph?

6/16/2007 3:05:14 PMEdd

Hows about some fill in data on the unit, as to its tube complement:
Possibly a pair of 12AX7's or 6EU7's sitting in the front end and a single 6V6..or a P/P pair of them used for A.F. output(s).
As well as the rectifier tube it uses..or possibly a solid state /selenium rectifier utilized.
Also the output transformers impedance taps options...possibly 0-4-8-16 ohms with a 70 V line output stuck on as its end .

Check and see if any of the lower number (power) series of these might be close enough for you to work with.

http://www.schematicheaven.com/hifi.htm
http://www.schematicheaven.com/hifiamps/bogen_cha-20.pdf

73's de Edd

--------------------------------------------------------------------------B/T---------------------------------------------------------------------------------

:Hi, Does anyone out there have a schematic for a David HT-16 phonograph?

6/16/2007 6:25:00 PMTom

:Hi ED,

This unit has (1) 6SL7, (2) 6V6, and a 5Y3. Someone has repaired it in the past and there is a pile of caps tied together in an effort to replace what should have been there. I don't know where to go from here to get it back to where it should be. There is a hum and one resistor runs pretty warm.

Thanks,
Tom

:Hows about some fill in data on the unit, as to its tube complement:
:Possibly a pair of 12AX7's or 6EU7's sitting in the front end and a single 6V6..or a P/P pair of them used for A.F. output(s).
:As well as the rectifier tube it uses..or possibly a solid state /selenium rectifier utilized.
:Also the output transformers impedance taps options...possibly 0-4-8-16 ohms with a 70 V line output stuck on as its end .
:
:Check and see if any of the lower number (power) series of these might be close enough for you to work with.
:
:http://www.schematicheaven.com/hifi.htm
:http://www.schematicheaven.com/hifiamps/bogen_cha-20.pdf
:
:73's de Edd
:
:--------------------------------------------------------------------------B/T---------------------------------------------------------------------------------
:
:
::Hi, Does anyone out there have a schematic for a David HT-16 phonograph?

6/16/2007 6:27:34 PMTom

This is a David Bogen HT-16

::Hi ED,
:
:This unit has (1) 6SL7, (2) 6V6, and a 5Y3. Someone has repaired it in the past and there is a pile of caps tied together in an effort to replace what should have been there. I don't know where to go from here to get it back to where it should be. There is a hum and one resistor runs pretty warm.
:
:Thanks,
:Tom
:
:
:
::Hows about some fill in data on the unit, as to its tube complement:
::Possibly a pair of 12AX7's or 6EU7's sitting in the front end and a single 6V6..or a P/P pair of them used for A.F. output(s).
::As well as the rectifier tube it uses..or possibly a solid state /selenium rectifier utilized.
::Also the output transformers impedance taps options...possibly 0-4-8-16 ohms with a 70 V line output stuck on as its end .
::
::Check and see if any of the lower number (power) series of these might be close enough for you to work with.
::
::http://www.schematicheaven.com/hifi.htm
::http://www.schematicheaven.com/hifiamps/bogen_cha-20.pdf
::
::73's de Edd
::
::--------------------------------------------------------------------------B/T---------------------------------------------------------------------------------
::
::
:::Hi, Does anyone out there have a schematic for a David HT-16 phonograph?

6/19/2007 10:57:43 AMEdd

Looks like that with your provided info that the amp with which you are working is back about ~ a decade from the info reference supplied....the "grandfather" of that unit.
See if this Bogen schema is in enough accordance with your circuitry, to be adequate for troubleshoting your unit. There may be a bit more "front end baggage", but I am assuming the "real meat" of the right end sides circuitry being coincident
If the canned electrolytics had been replaced with indididual units, I certainly can see a slew of them strewn all about the chassis.
I clarified some points of the schema, as well as done some mark up on it. C1 and C2 values clarified , C3 cathode bypass clarified.
The red boxed designatees are critical coupling caps, with no DC leakage tolerated.
The orange boxed units are the potential units, of your referencing to some "resistors getting hot".
I think that your amp willl be dependent upon the 6V6 output pair 's deriving their 1st grid bias via cathode resistor utilization , versus a separate bias supply....thereby, confirm that by there being the presence of that R32 --- 270 ohm common cathode resistor.
Any leakage into the first grids via C23-24 could upset your 1st grid bias and shift their mode of operation with an onset of increased current consumption and the overheating of the orange boxed units.
ALSO any leakage or high ESR on the electrolytics could cause a similar efffect.

Schema site:
http://img413.imageshack.us/img413/1635/davidbogensvcmarkedupct9.jpg

(Along with some adjunct OEM cap can data)

73's de Edd

----------------------------------------------------------------------------------BT------------------------------------------------------

:This is a David Bogen HT-16
:
:
:::Hi ED,
::
::This unit has (1) 6SL7, (2) 6V6, and a 5Y3. Someone has repaired it in the past and there is a pile of caps tied together in an effort to replace what should have been there. I don't know where to go from here to get it back to where it should be. There is a hum and one resistor runs pretty warm.
::
::Thanks,
::Tom
::
::
::
:::Hows about some fill in data on the unit, as to its tube complement:
:::Possibly a pair of 12AX7's or 6EU7's sitting in the front end and a single 6V6..or a P/P pair of them used for A.F. output(s).
:::As well as the rectifier tube it uses..or possibly a solid state /selenium rectifier utilized.
:::Also the output transformers impedance taps options...possibly 0-4-8-16 ohms with a 70 V line output stuck on as its end .
:::
:::Check and see if any of the lower number (power) series of these might be close enough for you to work with.
:::
:::http://www.schematicheaven.com/hifi.htm
:::http://www.schematicheaven.com/hifiamps/bogen_cha-20.pdf
:::
:::73's de Edd
:::
:::--------------------------------------------------------------------------B/T---------------------------------------------------------------------------------
:::
:::
::::Hi, Does anyone out there have a schematic for a David HT-16 phonograph?

6/19/2007 11:29:14 AMTom

Thanks again for your help. Tom

:Looks like that with your provided info that the amp with which you are working is back about ~ a decade from the info reference supplied....the "grandfather" of that unit.
:See if this Bogen schema is in enough accordance with your circuitry, to be adequate for troubleshoting your unit. There may be a bit more "front end baggage", but I am assuming the "real meat" of the right end sides circuitry being coincident
:If the canned electrolytics had been replaced with indididual units, I certainly can see a slew of them strewn all about the chassis.
:I clarified some points of the schema, as well as done some mark up on it. C1 and C2 values clarified , C3 cathode bypass clarified.
:The red boxed designatees are critical coupling caps, with no DC leakage tolerated.
:The orange boxed units are the potential units, of your referencing to some "resistors getting hot".
:I think that your amp willl be dependent upon the 6V6 output pair 's deriving their 1st grid bias via cathode resistor utilization , versus a separate bias supply....thereby, confirm that by there being the presence of that R32 --- 270 ohm common cathode resistor.
:Any leakage into the first grids via C23-24 could upset your 1st grid bias and shift their mode of operation with an onset of increased current consumption and the overheating of the orange boxed units.
:ALSO any leakage or high ESR on the electrolytics could cause a similar efffect.
:
:
:Schema site:
:http://img413.imageshack.us/img413/1635/davidbogensvcmarkedupct9.jpg
:
:(Along with some adjunct OEM cap can data)
:
:73's de Edd
:
:----------------------------------------------------------------------------------BT------------------------------------------------------
:
::This is a David Bogen HT-16
::
::
::::Hi ED,
:::
:::This unit has (1) 6SL7, (2) 6V6, and a 5Y3. Someone has repaired it in the past and there is a pile of caps tied together in an effort to replace what should have been there. I don't know where to go from here to get it back to where it should be. There is a hum and one resistor runs pretty warm.
:::
:::Thanks,
:::Tom
:::
:::
:::
::::Hows about some fill in data on the unit, as to its tube complement:
::::Possibly a pair of 12AX7's or 6EU7's sitting in the front end and a single 6V6..or a P/P pair of them used for A.F. output(s).
::::As well as the rectifier tube it uses..or possibly a solid state /selenium rectifier utilized.
::::Also the output transformers impedance taps options...possibly 0-4-8-16 ohms with a 70 V line output stuck on as its end .
::::
::::Check and see if any of the lower number (power) series of these might be close enough for you to work with.
::::
::::http://www.schematicheaven.com/hifi.htm
::::http://www.schematicheaven.com/hifiamps/bogen_cha-20.pdf
::::
::::73's de Edd
::::
::::--------------------------------------------------------------------------B/T---------------------------------------------------------------------------------
::::
::::
:::::Hi, Does anyone out there have a schematic for a David HT-16 phonograph?