New to me Eico ST-40

[910ken]

I picked this up locally. I will get some pictures up shortly but I wanted to order my electrolitics. Are the CE cans acceptable? I have used them on guitar amps before. If I choose to go individual will the JJ caps be a good choice? I have used Sprague before but they are pricey.

This is a very original integrated, including all tubes. I got it going tonight after major work on all pots, selector switch , mode switch and all sliders. All Very dirty. Definitely hums so first thing is a cap job.

Always glad to hear anyone s input.

Ken

 

[PakProtector]

The PEC modules that contain the phase splitter plate loads, coupling caps to the output tubes, and their grid resistors should get replaced with discrete components.
cheers,
Douglas

 

[RWood]

Using the JJ cans instead of the CE will save you some money. Order the clamps too, and use a step bit to hog out the holes.

I used their 50-50uF and 40-20-20-20.

 

[Dave451]

I have used all that you reference to good effect. I've seen some commentary about the CE's, but have had no issues with them (other than they are pricey) and they can preserve the top-of-chassis look if that's what you want. My main concern about them is that some of them only have a 55 degrees C temperature rating, which limits their usefulness sometime. I have tested new ones on my Sprague TO-5 tester and they always come up very good on capacitance value and leakage at max working voltage.

I like the JJ's (I tend to expoxy them onto the phenolic wafer instead of clamp them, but have done that too) and the blue F&T cans as well. Some of the JJ's are limited to around 70 degrees C max, so you have to consider that, too (look at the datasheets). I use 85 degree caps as a minimum, unless I know it's a low-heat environment (eg. a tuner or a pre-amp, maybe). Hayseed Hamfest does a great job with custom can caps and kits for certain brands/units, but they are about the same cost as CE's, and high quality (no affiliation, of course). The Sprague Atom axials are quite good, but pretty expensive.

 

[910ken]

That's right. I forgot about those PECs. It seams I read it is hard to find the values needed. Any suggestions? I will get some pics up tonight.

Thanks for the input. The JJs sure are tempting price wise.

 

[nj pheonix]

You can go hayseed hamfest too!

 

[sanford12]

Check out the mods for this amp.

 

[s-petersen]

That's right. I forgot about those PECs. It seams I read it is hard to find the values needed. Any suggestions? I will get some pics up tonight.

Thanks for the input. The JJs sure are tempting price wise.

The Eico HF-81 has the diagram for the PEC.
Sam Cogley made a board to replace them, I am not sure if he has any left.

 

[rudedogg]

I have used CE with success. I just lately went to Hayseed Hamfest. They will custom make multi-cans with better tolerance, better heat ratings, better pricing, and nicer looking as well!

 

[PakProtector]

That's right. I forgot about those PECs. It seams I read it is hard to find the values needed. Any suggestions? I will get some pics up tonight.

Thanks for the input. The JJs sure are tempting price wise.

I think I went down to 39k for the spit loads, and a .1 uF, 716P for the coupling cap...and of course, drop the 7591's grid resistors to something sane. I seem to recall using 120k but it is likely I went all the way to 100k.
cheers,
Douglas

 

[910ken]

Thanks everyone for your replies. I have been slammed with work the past two weeks so I haven't gotten my pics up. I will shortly although I might switch over to the Eico page. I will look up that info on the pecs.

Is the yahoo group still in operation? . It just didn't seam like much was happening nor did it seam navigable.

 

[billyz]

I just went thru one for a friend. He wasn’t interested in any upgraded coupling caps etc. it was humming and getting worse.
I replaced the can cap with a CE 40/40/40 .
And used the 3rd section for the single 30uf hanging right next to the can.
Also replaced the two cathode caps for the 7591’s , and finally a matched quad of JJ 7591’s. Cleaned all the pots / switches / contacts etc with deoxit and faderlube.

He is very happy and plays it all day long every day in his work shop / cave .

 

[RWood]

nor did it seam navigable

That is well put. I use the Yahoo group from time to time to try to get a schematic or assembly manual out of the Files section or if I am hitting a wall on something obscure. I don't know if it is still being moderated or if new members are being admitted. It was great in its day, an improvement over the alt.rec.newsgroup kind of technology, but has itself become a relic. They do have the three-part ST70 assembly manual, though, which, if you haven't gotten, you should.

 

[billyz]

BTW, years ago I had a brand new jj 50/50-500v can bad from the get go. About that same time I kept getting poor results from their tubes as well. So I have refrained from using them . I still don’t trust their gz34 as I have had many issues with them . I guess they are cheap for a reason .

 

[910ken]

That's a great idea for the 30uf, hanging right under that can. I have read mixed opinions on the CE cans but here's another happy customer. Thanks Billy.

I just hit all the controls with deoxit again and this time used the fader lube and I think I got it . I seam to find really dirty selector swithes. They don't come clean very easily.

Took my pics as well and will get them up tomorrow, er, later today. I worked late tonight, limo bus driver, so I got a late start. HVAC during the day though.