henry4841

I kind'a see it.

I just happened to notice what a nice wood case having restored a few myself. Congratulation on nice find. Bet sounds as good as looks.

I may have been one of those that said Klipsch ran out of brass screws and intentionally used steel until stock restored. Could as well have been some newbie or careless veteran just grabbed the wrong box of screws from the supply room. S**t happens. No real harm done, I am sure owner was well satisfied listening with steel screw for decades without an issue. Just replace with brass if found in your network and be more happy with your speakers.

Very nice, I have always liked those old Fisher receivers. Wood case looks extremely nice. Was it repaired, restored along with the electronics?

I also would love to see schematic.

Splitting frog hairs is what audiophiles do on forums. Technicians that repair audio gear use what they have in stock and think, good enough while doing so.

The early Heritage crossovers were not that critical of tolerances in the parts being mostly 1st order with little steeper 3rd order on the tweeter. Mainly to protect that delicate tweeter because of tweeter failure by idiots playing too loud. This topic comes up again and again like it was the most terrible thing in the world having a steel screw instead of a brass one. It would take someone with extraordinary hearing to tell the difference in a blind test.

Back to screws used in AA networks again. Circles around regularly on the forum. The truth is the difference between ferrous and non-ferrous screw in circuit is not enough to really be a serious concern. Probably the real reason steel was used was when there was a supply problem with the brass screw. Leave be or replace if concerned engineers did not know what they were doing. As far as iron core saturation, will not ever be a problem in a Klipsch designed crossover. Iron core is plenty good enough, at least true electronic engineers believe so. Design of an electronic component is far more important than resorting to expensive non-needed parts for improvement. What many call improvement is just different sounding. Bench testing with someone that knows what they are doing is the only true test. That and listening panel with trained ears. But back to OP finding LaScala's. Great score. Replace what needs replacing and leave rest alone for now.

On peaks, not average. Most any quality amplifier will work fine for most that use Klipsch speakers. Think quality over quantity because horns and efficient speakers can be very unforgiving.

Certainly not an expert myself. Smart enough to google though. https://www.youtube.com/results?search_query=oscilloscope+measuring+capacitors+

Now that is an old one for sure. I have 6 or so old scopes but none that old. My repairs of old scopes has been hit or miss. Most times it is a power supply problem though. But getting back to reforming old caps, unless the equipment is decades old I do not go through the trouble myself. Does not hurt to be too careful though. To answer the how question, slowly bring the power up to approximately 60V's and hold it awhile there then slowly bring it up to line voltage from there.

I have a number of scopes and like Seti really like my old analog scopes. Crap shoot finding a good working one but when you do you will love the trace it provides. Still I probably use my digital scope more being it is so easy to get numbers. Nothing fancy for me, a Hantek DSO5102 is plenty good enough for audio work.

Making some progress.

Really nice and cool looking. I would be proud as I am sure you are. Five watts are all that is needed with our speakers.

More pictures of the parts removed from old build waiting to find their new home. The sockets that hold the 300B tubes are not made where you can just drill a hole and be done. I drilled as big a hole as possible with what I have then nibbled out with my jig saw and new blade where the pins go through the chassis. Should look professionally installed when finished with no gaps. Just need to start putting everything together in the next few days, weeks. Old and slow.

This is a project I have been working on for a few weeks. It takes me that long making and prepping a chassis. A lot of work goes into making a presentable case to house a special amplifier. I built a SET 300B probably close to a decade ago on a Bud chassis and it is one of my favorites. I would like to think my case work and electronic skills have improved since building that amplifier so I decided to take it apart and start a new build but using most of the old parts. I did order a new PS transformer with some more secondary voltage but I already have some excellent One Electron output transformers so their is no need in replacing them. Below is the progress I have made with more reports and pictures forth coming.

When you go to someone's house you play by their rules. Rules have changed and some do not like it. I get it but it is still their house we play in. One change that is great as far as I am concerned is Klipsch is in charge of this forum now and not a select few long time members and their friends. Much, much friendlier place now. Cannot remember the last time their was a verbal fight. Mods "nip them in the bud" now as Barney use to say. Perhaps more and more visitors will join and post now. Some of the old members were down right rude to any newbie's post. Constant verbal fights between members was the norm. Not a good image for any company.

I think you may be confusing the Firstwatt J2 with the Aleph J. The Aleph J uses the more common IRFP240 mosfet rather than power J-fets. Those semi-south J-fets, forget the number off hand, are unattainable unless you are willing to fork over more money than I am willing to pay for them. Semi-South went out of business years ago. I think you mean this kit being out of stock at the diyaudio store. https://diyaudiostore.com/products/aleph-j-mosfet-and-jfet-kit?variant=39321292931145 The kit is a good deal for those that do not wish to match the parts themselves but it can be built buying the parts and matching them yourself from Mouser.com. That is all but the 2SJ74's will have to be bought at the store but they are in stock for $45. https://diyaudiostore.com/collections/jfets/products/matched-jfets?variant=39335246954569 I buy my IRFP240's in quantity of 25 in a tube. That way you will have pretty well matched mosfets without any testing when they are from the same run. They come that many in a tube, 25. I have verified this many times with most of the 25 in a tube, close enough matched for most builders.

Do you mean the power J-fets from Semi-south?

Very nice, and I heard they sound really good.

When doing repairs to electronic equipment I find heat to be the biggest contributor to electrolytic failure. When I see a board upside down inside the chassis of an old receiver I know most if not all the capacitors on that board will need replacing.

Old farts like myself are allowed to make mistakes. 😃 Thanks to Travis for fixing it.

The F5 and F6 are very good amplifiers just too unforgiving for me. A lot of the Firstwatt offerings are much the same with different front ends and the same output configuration. Both the F5 and F6 have one pair of output transistors for each channel. In general terms the more pairs of output transistors an amplifier has the better the sound is going to be. Two of my favorites are the one just for diyer's called the BA-1 and BA-2 with the BA-3 front end. The BA-2 is basically the F4 with the BA-3 front end. The latest project is the M2X where you have the F5 follower end stage with multiple front ends one can build and swap in and out. Neat for those that like to play. What you probably did not like about the original M2 was the transformer coupled front end. It does add it's own signature to the sound but other than that very much like the F5 and F6 circuit wise. Just to set the record straight, there are no culls in the Firstwatt lineup. Perfect for Klipsch speakers if you desire a tube sound in a SS amplifier.

I have built all of the Firstwatt clones. Some are just boards now taken out and replaced with some other boards I like better. This Aleph J is one of my favorites, single ended which is also my favorite type of amplification. Very tube like sound. At the present time I have 6 complete up and running Firstwatt clones. The boards taken out and replaced just from memory are the F6, F5 and a version of the F7. Nothing wrong with these three, they just are not my cup of tea with horns.

And pictures before and after.