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    Building, troubleshooting and testing of these amplifiers should only be
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Cheap SE EL84

Guys,

I just ordered this little puppie from Lighthouse Electric http://www.lh-electric.4t.com/sta44.htm. Anyone of you guys build, tested and/or reviewed this one? There are only a few threads and sites but none from DIY-people that actually built one. It is being sold since Feb for $229 and I cannot imagine that I am the first to do so. If this is the case, however, give me some time and I will get back to the forum for a complete overview in a few weeks.

DocLorren

ps. Any more amps of this type out there besides LH and Bottlehead that you know of?
 
DocLorren said:
I just ordered this little puppie from Lighthouse Electric http://www.lh-electric.4t.com/sta44.htm. Anyone of you guys build, tested and/or reviewed this one?

Only seen the web-site... this was brought up in another thread... even if you intend to only use it for parts & chassis (all the right bits to build an RH84) it looks a bargin.

The input stage looks like it is on a PCB, but you could always rectify that later. The LF spec looks optimistic given the size of the OPTs.

dave
 
DocLorren said:
Guys,

ps. Any more amps of this type out there besides LH and Bottlehead that you know of?

At $229 shipped, including enclosure, that amp is a very good price. It has some very nice features like the ability to switch between 4/8/16 ohms. A stand by switch so that you can wait till the tubes heat up before you kick in the B+ is also useful. Plus a choked PS is always nice.

The $139 K-12M is also a good price, but you have to add shipping and an enclosure so your total costs will ring in near $230. The K-12M is only for an 8 ohm load and does not have a great PS.

I built the K-12M .. you can visit my website for more info. Many people have enjoyed the K-12M. Had this EL84 kit been available at the time, I would have taken a chance on it.

Please do let us know how you make out.
 
Re: Re: Cheap SE EL84

GG said:
Please do let us know how you make out. [/B]


Well, that is what I will do then. First off just the kit 'as is'.
And a modified model probably later on to see where improvements can be implemented easily like the OPT's, caps, hardwiring etc.
Any structural weaknesses in the schematics that should be addressed in the modified model you can think of right away?
 
Se El84

Ik vind de ingangstrap veel te complex. THE LESS, THE BETTER!! En een ECC82...foei! Very lazy and dull-sound.
Zeer veel ge-experimenteerd met SE EL84 eintrappen:

# Mijn tips:
1. vervangen de ECC82 door de 6CG7 EH (Electro Harmonix) of de RCA 6CG7 met Side-getter! Amazing improvement!!!
1.a. Instelling 6CG7: Ra : 100K, Rk 1K2 , Ub 260-280V. DC

2. Buisgelijkrichting: absolute topper is de 6CA4/EZ81 EH (Electro Harmonix): gemak, ruimte, detail, body/drive.

My opinion after a lot of experimenting with SE EL84:
forget de lazy and dull sound ECC82/5814A family; inputstage to complex in my opinion...;
golden tips:

1. input/driverstage: 1/2 6CG7 EH or 1/2 RCA 6CG7 with site-getter! Amazing improvement!!!
1.a. feeding the 6CG7: Ra : 100K, Rk 1K2 , Ub 260-280V. DC

2. Tube rectifier: 6CA4/EZ81 EH (Electro Harmonix): lots of detail, headroom, easy, emotional sound, a lot of body/drive.

(Enough sensivity to work without pre-amp. at 94dB plus speakers also. With EL84M/6BQ5WA from Sovtek, Philips Miniwatt El84 and EL84 EH [Electro Harmonix]).

(schema enclosed)



Dogie
 

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DocLorren said:
Guys,

...ps. Any more amps of this type out there besides LH and Bottlehead that you know of?


If you are talking about inexpensive amp kits there is the S5 amp (aka K12) from Arizona HiFi. About $140 USD, about 8 WPC in a P-P designed by George Fathauer. I built one a couple years ago and it was a big mistake. I can't stop building tube amps now! :D

The S5 sounds pretty good, great actually for $140. I do think it would benefit from bigger, better OPTs and I believe the PS is only just sufficient so there is room for experimentation.

I also built a Lighthouse Electric STA-1 LG preamp which I like very much. It uses 3 ECC82 and gain is about 5.6. I changed the heaters to DC to eliminate 60Hz hum. I also just finished switching out the .022uF caps in the bass circuit for .033uF which reduces bass gain and balanced the overall sound. (Both those fixes are on the LE website now.)

LE has given me good support, answering every question I've emailed to them very promptly. I wouldn't hesitate to build that new little amp.