New to me HH Scott LK 72

[MadcapLaughs]

So I finally made the leap into tube electronics after a "solid" three years of very nice classic integrateds from Yamaha, Sansui, etc. I just picked up an LK 72 for a good price, it had new orange caps, an array of original but in spec Scott tubes, and was cleaned and biased. The transformation in my system was immediatly noticeable, with a good set of altecs this has already earned a permanent spot for me. Something I was always apprehensive about was whether the Scott could keep up win a variety of music styles, (since most posts seem to reccomend it for vocal or acoustic....yawn). I made sure to hit the most abrasive LPs first; Sabbath, the Stooges, King Crimson and complex, overloaded tracks from Aphex twin, etc. the Scott simply kicked so much ass with all the above. It added a nice analogue bubbly film around electronica while still retaining so much detail, I honestly was not expecting that.
Of course most people know how well the old Scotts can handle jazz and classic rock, but I just wanted to make clear from my very brief experience that if anyone wants to jump into tube audio, in my estimation you will not sacrifice much in terms of versatility of music genres should you switch to tubes...provided you have the right speakers of course.

Anyway here is pic. Anyone have any input of similar experience using tube amps for music other than Dizzie Gillespie or Joni Mitchell? (NO offense to either of them by the way).

Also is this amp getting enough ventilation in the audio rack I have? It feels like you can cook chicken on that shelf.

EDIT: I forgot to mention how dumbfounded I am that despite what I have heard, this tube amp has better bass response with the same speakers than a variety of 80wpc solid states I have used in the past. Also the volume output seems to match them as well!

 

[soundmotor]

They run hot and the amp could be used with or without the case. Without there is plenty of air circulation. If the output tubes are fine and it biases up OK don't worry.

 

[bean_counter]

EDIT: I forgot to mention how dumbfounded I am that despite what I have heard, this tube amp has better bass response with the same speakers than a variety of 80wpc solid states I have used in the past. Also the volume output seems to match them as well!

You are using suitable speakers. Too many do not, then are disappointed and blame the amp. With the Scott at 35 wpc (IIRC), the 80 wpc amps are only 3dB or so louder, likely not an issue at all on your speakers.

Well implemented push-pull tube amps should be competent on any music. I recognize that SE amps have a magic to them that PP gives up, but I find few can play large, complex works well - excepting exotics speakers and/or amps, of course.

Welcome to the tubes disease. Try some PP, no feedback directly heated triodes some time; 2A3's or 6B4G's can be 8-12 watts of heaven if your speakers are sensitive enough.

 

[Patrice B]

Be sure that all main caps were replaced, including the PS can caps...

If it is the case, enjoy with any type of music!

 

[primosounds]

There are a lot of misconceptions about tubes and a lot of people are surprised about the sound qualities from tubed equipment. As with most things one must be skeptical about what you read and see on the internet and you found out that a live auditory experience was the best way to appreciate the differences.

 

[crispycircuit]

One of my all time favorite amps. Recap is a time consuming pain. Hopefully yours is done?

 

[trainbuftony]

I have had the same experience with my Scott amps, they handle everything with ease, and sound great provided you let them warm up for 20 to 30 minutes before expecting 100% performance. I routinely play everything from metal to jazz to reggae to pipe organ music, and it all sounds very clean and powerful. Makes no difference if it is the Scott 299D, LK72, or just the power amp section, the 208. They were on to a great design with these amps, and I plan to continue collecting and restoring them whenever I find them. They are something special and a thing of beauty is a joy forever.

 

[triode17]

I have never heard of a musical restriction of any tube amp. That's absurd! I own an LK-72 myself and it kicks ass! You have plenty of ventilation there. Used JJ 7591's in the outputs and they sound very good (despite what some people say). No need to buy vintage Westinghouse or Sylvania's.
There is a 'rule' that each tube Watt equals two SS Watts. It felt like I added a subwoofer the first time I broke cherry with tubes. I can't listen to SS anymore, just sounds too flat across the soundstage, without enough depth. Plus all the feedback that's needed flattens the dynamics. Welcome to the club!!
TUBES RULE!!!

 

[Fairlane]

Nice score on the Scott. I love mine and find it sounds great great with any type of music.

 

[kvflyer]

My favorite, the brown face plate version. Did you know that the brown face plate came in two versions? One has a pull on switch on the volume control and the other one is the turn clockwise to turn on. You can see mine in my avatar. Nice, glad you got it.

(Your worthless trivia today, the face plate thing)

 

[MadcapLaughs]

Thanks for the responses all, here is a brief description of work done on the amp from the Craigslist post:

"Fully recapped with orange drop 716P caps and Solen caps
Brand new NOS tubes 1 - Mullard 5AR4/GZ34, 4- Rca 7591, 2 - GE 6GH8A, 4 - Sylvania/ Baldwin 12AX7
New can caps from Hayseed Ha fest
All out of spec resistors replaced to keep vintage sound
All switches/pots cleaned and lubed".

Anyways this amp has been completely restored to the best of my limited knowledge. Here is a few more pictures that show the overall wiring of whoever had assembled this kit. The guy I bought it from is a electrician who performed the recap and additional work. Anyone know if the underside of this amp looks well put together? I think it looks like a birds nest but that's my untrained eye judging the situation.... A visit to an experienced tube tech may be in order to verify the work the seller did. Anyways this amp is so awesome and it makes me wish I had never sold the Altec Valencias (I foolishly parted with them after using them with an old transistor amp, the sound was not smooth to say the least).

 

[Patrice B]

My favorite, the brown face plate version. Did you know that the brown face plate came in two versions? One has a pull on switch on the volume control and the other one is the turn clockwise to turn on. You can see mine in my avatar. Nice, glad you got it.

(Your worthless trivia today, the face plate thing)

Mine is pull-on...

 

[Patrice B]

Good to know that all recap is done, good for another 25-30 years...

 

[drew_t]

Anyways this amp has been completely restored to the best of my limited knowledge. Here is a few more pictures that show the overall wiring of whoever had assembled this kit. The guy I bought it from is a electrician who performed the recap and additional work.

You can see in one of the photos that the original selenium rectifier is still there (rectangular thing next to one of the bundles of wire coming out of the power transformer). These are typically replaced in restorations with a silicon equivalent part, which is more reliable and costs pocket change.

 

[GD70]

You can see in one of the photos that the original selenium rectifier is still there (rectangular thing next to one of the bundles of wire coming out of the power transformer). These are typically replaced in restorations with a silicon equivalent part, which is more reliable and costs pocket change.

I saw that also. When I restored mine, replacing the selenium rectifier was one of the first things mentioned I should replace. Got mine from RatShack for a couple bucks.

To the OP, your amp looks great! Can you post some close ups of the face?
I currently have mine hooked to my 1963 KLH Six's and it sounds great! I listen to a lot of electronica, funk, and live stuff and the Scott never feels lacking with any genre.
I had my ADS 910's hooked up to it, they are 93db sensitivity and it sounded very good, but it was clear 35wpc was not enough for these speakers.
Enjoy your LK-72!

 

[GD70]

Thanks for the responses all, here is a brief description of work done on the amp from the Craigslist post:

"Fully recapped with orange drop 716P caps and Solen caps
Brand new NOS tubes 1 - Mullard 5AR4/GZ34, 4- Rca 7591, 2 - GE 6GH8A, 4 - Sylvania/ Baldwin 12AX7
New can caps from Hayseed Ha fest
All out of spec resistors replaced to keep vintage sound
All switches/pots cleaned and lubed".

Anyways this amp has been completely restored to the best of my limited knowledge. Here is a few more pictures that show the overall wiring of whoever had assembled this kit. The guy I bought it from is a electrician who performed the recap and additional work. Anyone know if the underside of this amp looks well put together? I think it looks like a birds nest but that's my untrained eye judging the situation.... A visit to an experienced tube tech may be in order to verify the work the seller did. Anyways this amp is so awesome and it makes me wish I had never sold the Altec Valencias (I foolishly parted with them after using them with an old transistor amp, the sound was not smooth to say the least).

It look so

Thanks for the responses all, here is a brief description of work done on the amp from the Craigslist post:

"Fully recapped with orange drop 716P caps and Solen caps
Brand new NOS tubes 1 - Mullard 5AR4/GZ34, 4- Rca 7591, 2 - GE 6GH8A, 4 - Sylvania/ Baldwin 12AX7
New can caps from Hayseed Ha fest
All out of spec resistors replaced to keep vintage sound
All switches/pots cleaned and lubed".

Anyways this amp has been completely restored to the best of my limited knowledge. Here is a few more pictures that show the overall wiring of whoever had assembled this kit. The guy I bought it from is a electrician who performed the recap and additional work. Anyone know if the underside of this amp looks well put together? I think it looks like a birds nest but that's my untrained eye judging the situation.... A visit to an experienced tube tech may be in order to verify the work the seller did. Anyways this amp is so awesome and it makes me wish I had never sold the Altec Valencias (I foolishly parted with them after using them with an old transistor amp, the sound was not smooth to say the least).

The underside of yours looks pretty typical.
Nice to have a fully recapped amp.

 

[macgolf]

Nice Scott! The one ventilation tip I picked up here was to allow plenty of underside ventilation to help with the "chimney effect" and it looks like you've got that. Enjoy and I like your choice of speakers.

 

[MadcapLaughs]

Hey GD70, I think I watched some of your video uploads of the Scott with the KLH 6 speakers and the ADS L910 speakers. The Scott sounded like it was blasting the ads pretty loud, but it is just a YouTube upload after all. Anyway, can the Scott deliver some good power to the Klh? I might pick up a pair of those to run as an alternate option to the Altec boleros I have set up now. And any other speaker suggestions for this amp (aside from Altec or klipsch) would be much appreciated!

Also I know that phono stages have lower gain than line inputs in general, but is there a tube for this phono stage that anyone would reccomend as providing more power or gain to the signal? If I loose clarity or any other characteristics I wouldn't mind, I would just like a tube that has a reputation for power output that will work in the Scott.

 

[billyz]

Just about any 12ax7 will have all the gain and power you could want.
Not that they all sound the same.
For the budget minded try the sovtek 12ax7 LPS . My all time favorite is the amperex bugle boy( most expensive).
The old Mullards are warm n fat sounding. Telefunkens are extremely neutral and last forever. Chinese variants usually sound harsh and edgy to me , not reliable.
Can not go wrong with the RCA 7025 or blackplate. Other good ones are anything made in the USA , old organ pulls.
Of course these must all be tested and listened too in the circuit.

 

[Crammit]

It look so

The underside of yours looks pretty typical.
Nice to have a fully recapped amp.

I saw those videos, too. Awesome sound. Who in the world does that version of "Don't Let Go"? I like it more than the original. Have listened to it a few times. Can't find who it is.