Vintage DIY Stereo Integrated Amp w/ Pics

[XEagleDriver]

My Dad and I (mainly him) designed from scratch and built this integrated amp when I was in High School (circa 1976-77). He was a EE working at TRW at the time and I was contemplating following his career choice. He sketched the circuit from memory and hand drew the schematic. We etched the circuit boards, soldered the components, and built the oak cabinet all by hand.

I used the amp for the remainder of HS and at the USAF Academy once we were "allowed" stereo privileges. After graduating in 1982, the amp went into storage in my Dad's basement for the last ~28 years!

Sadly, my Dad died on 13 Dec 09. On a trip this month to help my Mom settle affairs I found the amp in the basement. Curious if it still worked, I plugged it in and the lights all illuminated. I did not have speakers to test it with, but took a chance and shipped it to my home in SC.

It arrived in perfect condition (whew) and I hooked it up to a pair of sacrificial lamb Radio Shack speakers and all went well. Now with some confidence, I hooked it to a pair of Def Tech PM1000s and used a Sansa MP3 player as a source. It sure sounds sweet to my ears, probably a lot of nostalgia involved, but sweet none the less!

Pics are in: http://forums.audioholics.com/forums/album.php?albumid=9

Thanks for listening,
XEagleDriver

 

[dkane360]

wow thats pretty neat. thanks for sharing! any interior pics?

 

[njedpx3]

My Dad and I (mainly him) designed from scratch and built this integrated amp when I was in High School (circa 1976-77). He was a EE working at TRW at the time and I was contemplating following his career choice. He sketched the circuit from memory and hand drew the schematic. We etched the circuit boards, soldered the components, and built the oak cabinet all by hand.

I used the amp for the remainder of HS and at the USAF Academy once we were "allowed" stereo privileges. After graduating in 1982, the amp went into storage in my Dad's basement for the last ~28 years!

Sadly, my Dad died on 13 Dec 09. On a trip this month to help my Mom settle affairs I found the amp in the basement. Curious if it still worked, I plugged it in and the lights all illuminated. I did not have speakers to test it with, but took a chance and shipped it to my home in SC.

It arrived in perfect condition (whew) and I hooked it up to a pair of sacrificial lamb Radio Shack speakers and all went well. Now with some confidence, I hooked it to a pair of Def Tech PM1000s and used a Sansa MP3 player as a source. It sure sounds sweet to my ears, probably a lot of nostalgia involved, but sweet none the less!

Pics are in: http://forums.audioholics.com/forums/album.php?albumid=9

Thanks for listening,
XEagleDriver

Awesome! Thanks for sharing ... Sounds like great father/son relationship building project.

I built some Dynaco equipment in the early 70s, Amp and Tuner

Take Care,

Forest Man

P.S. --Just think if you had become an EE

 

[XEagleDriver]

Not brave enough yet

wow thats pretty neat. thanks for sharing! any interior pics?

Dkane,

I am trying to remember exactly how we secured the face and back plates and circuit structure inside the wood four-sided container. Until I get a clearer idea on what we did, I am reticent to try and go inside for fear of damage.

Cheers,
XEagleDriver

 

[XEagleDriver]

Funny part is I did, but then went flying!!

Awesome! Thanks for sharing ... Sounds like great father/son relationship building project.

I built some Dynaco equipment in the early 70s, Amp and Tuner

Take Care,

Forest Man

P.S. --Just think if you had become an EE

Forest Man,

Funny part is, I did become a EE once the Air Force said I was not pilot qualified as an Academy freshman. Then in my senior year, they reversed course and I went to flight training and never actively used the EE degree (after beating my head against the wall for four years!).

I eventually did apply the EE and pilot experience in designing a F-15C full-visual flight simulator, but that was at the system design, vice circuit design, level.

Cheers,
XEagleDriver

 

[njedpx3]

Forest Man,

Funny part is, I did become a EE once the Air Force said I was not pilot qualified as an Academy freshman. Then in my senior year, they reversed course and I went to flight training and never actively used the EE degree (after beating my head against the wall for four years!).

I eventually did apply the EE and pilot experience in designing a F-15C full-visual flight simulator, but that was at the system design, vice circuit design, level.

Cheers,
XEagleDriver

LOL great direction. I was in college for EE and got a summer job as a computer operator and decided to take a computer programming course. Got EE but spent career in IT


Peace, Good Sound and Good Video,

Forest Man

P.S.- Anyone remember Heathkits ?

 

[highfigh]

My Dad and I (mainly him) designed from scratch and built this integrated amp when I was in High School (circa 1976-77). He was a EE working at TRW at the time and I was contemplating following his career choice. He sketched the circuit from memory and hand drew the schematic. We etched the circuit boards, soldered the components, and built the oak cabinet all by hand.

I used the amp for the remainder of HS and at the USAF Academy once we were "allowed" stereo privileges. After graduating in 1982, the amp went into storage in my Dad's basement for the last ~28 years!

Sadly, my Dad died on 13 Dec 09. On a trip this month to help my Mom settle affairs I found the amp in the basement. Curious if it still worked, I plugged it in and the lights all illuminated. I did not have speakers to test it with, but took a chance and shipped it to my home in SC.

It arrived in perfect condition (whew) and I hooked it up to a pair of sacrificial lamb Radio Shack speakers and all went well. Now with some confidence, I hooked it to a pair of Def Tech PM1000s and used a Sansa MP3 player as a source. It sure sounds sweet to my ears, probably a lot of nostalgia involved, but sweet none the less!

Pics are in: http://forums.audioholics.com/forums/album.php?albumid=9

Thanks for listening,
XEagleDriver

You have to love the chicken head knobs. Looks like a nice piece- the mic and phono inputs are isolated from the chassis and it has an outboard power supply- both are good design aspects.

 

[TLS Guy]

My Dad and I (mainly him) designed from scratch and built this integrated amp when I was in High School (circa 1976-77). He was a EE working at TRW at the time and I was contemplating following his career choice. He sketched the circuit from memory and hand drew the schematic. We etched the circuit boards, soldered the components, and built the oak cabinet all by hand.

I used the amp for the remainder of HS and at the USAF Academy once we were "allowed" stereo privileges. After graduating in 1982, the amp went into storage in my Dad's basement for the last ~28 years!

Sadly, my Dad died on 13 Dec 09. On a trip this month to help my Mom settle affairs I found the amp in the basement. Curious if it still worked, I plugged it in and the lights all illuminated. I did not have speakers to test it with, but took a chance and shipped it to my home in SC.

It arrived in perfect condition (whew) and I hooked it up to a pair of sacrificial lamb Radio Shack speakers and all went well. Now with some confidence, I hooked it to a pair of Def Tech PM1000s and used a Sansa MP3 player as a source. It sure sounds sweet to my ears, probably a lot of nostalgia involved, but sweet none the less!

Pics are in: http://forums.audioholics.com/forums/album.php?albumid=9

Thanks for listening,
XEagleDriver

Your father was cutting edge for that date. It is entirely built from ICs right up the output driver devices! I don't see any speaker protection from output device failure, and the output devices are direct coupled to the speaker. Even in commercial designs of that era, speaker protection from DC off set from device failure was only just coming in. So you need to be aware that your speakers are at risk from output device failure.

I don't recall much of that going on at that time in commercial products, certainly not Japanese receivers of that era.

The first unit that I had that made extensive use of IC circuits, was my Studer/Revox A 700 tape recorder. I purchased that in 1974.

 

[XEagleDriver]

Got Brave and Opened it Up (pics added to album)

wow thats pretty neat. thanks for sharing! any interior pics?

Dkane,

Studied the exterior some more and "remembered" how we secured the face plates. We used four screws on the bottom to secure four square-wood posts each connected to one of the standard mounting bolt cutouts on the face plates (2 front and 2 back). With the screws removed, the entire interior slides out of the four-sided oak wood shell as one piece.

The interior pics have been added to the album (link is in first post).

What I found once open:

1) A very small rodent had at some time in the past 30 years made a nest inside with string and fuzz. Fortunately, he/she did not have an appetite for electrical components or wires as far as I can tell Removed the "nest"! Otherwise surprisingly free of dust and dirt.

2) The overall structure has components attached to five sub-structures; a rear faceplate, a front faceplate, two interior "rails" (the one pictured on the left is the RIGHT Channel and the one pictured on the right is the LEFT Channel) and a small board between the rails.

3) I believe the small board between the two (pictured near top center) is most of the pre-amp circuit.

Enjoy,
XEagleDriver

 

[XEagleDriver]

To save a bunch of scrolling, here is the picture album link:

http://forums.audioholics.com/forums/album.php?albumid=9

XEagleDriver

 

[njedpx3]

To save a bunch of scrolling, here is the picture album link:

http://forums.audioholics.com/forums/album.php?albumid=9

XEagleDriver

Very nice neat, clean wiring.

I need to take a picture of my LED clock I built in 1976 ... wow 34 years ago ... it was novelty back them

Also watchout for rodents, but ants are worse. I had ants short out an air conditioner relay .. I guess they liked the "buzz", hundreds and hundreds if not thousands died and their extoskeletons finally open circuited the relay.


Peace, Good Sound and Good electornics,

Forest Man

 

[XEagleDriver]

Two final pictures added to the picture album:

1) The insides being removed from cabinet
2) The view from the bottom, clearly showing the small circuit board.

Funny, I thought we had etched some circuit boards, but we actually used fiberglass boards with predrilled holes and soldered each component into place, connecting all by wire.

XEagleDriver

 

[jeffsg4mac]

Neat! the thing looks to be in fantastic shape. I would love to listen to it, and I bet it will last forever.

 

[lsiberian]

Looks fantastic and sounds fantastic. Don't take it apart we want it to work forever.