1979 Electro Harmonix hot tubes schematic. Anyone have this?

[Slobrain]

hey folks,

Anyone have the schematic to the original electro harmonics hot tubes from the 79 to 80 period?

Thanks

[doctor]

hey folks,

Anyone have the schematic to the original electro harmonics hot tubes from the 79 to 80 period?

Thanks

Try this

[Mark Hammer]

Note that it WILL run off a 9v battery. But the battery won't last you a long time. It won't fizzle out mid-gig, but it won't go for the months that it does in many other pedals.

[Slobrain]

Thanks Doctor,

By the way, how does this pedal sound compared to todays new pedals? I think Neal Schon used this on the Journey Infinity album.

Thanks

Slobrain

[kleuck]

Great pedal, realistic tube sound, touch-sensitive, can be noisy.
Snarling Dogs overdrives (Blue-Doo, Black Dog & Tweed-E-Dog) were just slightly modified Hot Tubes (voicing)

[Mark Hammer]

Most 4049-invertor-based overdrive pedals tend to enjoy a good reputation, and the HOt Tubes is no exception. Kleuck is absolutely correct in asserting that those Snarling Dogs pedals are basically a Hot Tubes in a small box without a transformer (see, I told ya they can work on a battery!).

The Way Huge Red Llama, itself derived from the Craig Anderton EPFM Tube Sound Fuzz, is another one, and so is the Blackstone MosFet Overdrive. The overdrive channel for many of the Laney solid-state amps is also based around a MosFet inverter.

Opinions may vary but I would describe the HT as having a nice gutteral "grunt". It also has a fairly hot output, which makes it suitable for pushing real tubes in a pleasing way.

[Chef Boyardee]

Can someone please repost the schematic of the EH Hot Tubes

Thnx

[Mark Hammer]

http://www.freeinfosociety.com/media/images/4305.gif

The schematic shows a transformer-based power supply. Note that it WILL run just fine off a 9v battery. It just won't run for a very long time on one.

[Chef Boyardee]

http://www.freeinfosociety.com/media/images/4305.gif

The schematic shows a transformer-based power supply. Note that it WILL run just fine off a 9v battery. It just won't run for a very long time on one.

Thanks Mark! Much appreciated.

[g1]

Mark, the attachment didn't work, probably needs resizing.
Here it is:

[Mark Hammer]

Thanks for that.

I am concerned that the schematic appears to stipulate a 4049BE chip and not UBE type. It has always been my understanding that unbuffered hex invertors are needed for such overdrives. I know that I have a UBE in mine and it works as intended. I have not tried a BE type. Heck, I don't even have one of those.

[Slobrain]

Looks like Electro Harmonix is now building the old version again in a smaller box, not sure how the sound stacks up to the old ones though...

Cheers

[Mark Hammer]

No reason to expect it would be any different. A 4558 and 4049UBE in 2013 is no different than one in 1979. On the other hand, Mike Matthews himself said that if you took any 4 consecutive Big Muffs off the line at that time, they would all sound different. Conceivably making these with SMD parts (like all the Nano series) will yield consistent tone.

The only reason to maybe expect a tiny difference is the power supply. As noted earlier, the original used an on-board power supply because the current drain on the battery was a little high-ish. It is possibly that the current available from the transformer, vs a slightly used battery, would yield a different transient response. On the other hand, how many of these puppies would NOT be externally powered these days?