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Building a SE84 clone (Read 16846 times)
JBzen
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Building a SE84 clone
02/07/22 at 15:50:53
 
After a week studying various schematics available online for Steve's SE84, I got up enough nerve to order the parts. I would have much rather let his crew build one but at my age the wait is unbearable.
I still need to outsource the output trannies. There is a couple of suppliers on ebay. One is from Greece and another China. China's offering can be here by next month but it is a rather light weight transformer.  Greece's offering seems A quality but won't be delivered until April. Encor is a May delivery. I may just order the Chinese to get the amp up and running then find better ones in time.
The cost is around $600 for electrical parts with tax and shipping. The cost also includes anniversary mods and lightweight trannies.
Here is a pic of my worksheet.



John
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JBzen
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Re: Building a SE84 clone
Reply #1 - 02/08/22 at 17:31:48
 
I found these on Amazon.



Lightweights but will be here this week. I might even swap out the Edcors in my Zkit1 build when the point to point is up and running. Then put the 5 watters in the Zkit1 and power a set of Tiny Radials in the office.

Now off to the local tin shop to find some 16 gauge steel for the chassis. Looks like February is going to be busy around here!

John
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bobc
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Re: Building a SE84 clone
Reply #2 - 02/09/22 at 16:38:01
 
I have these Amazon transformers in a decware clone in my basement. They sound pretty good considering the price, I haven't been able to find any published specs. I also have tried the 9.8K/6ohm edcors, these are very good. OPT affect sound greatly. I haven't heard an actual decware / UFO, but to me after some experimentation, I had a pair of 6.5K transformers wound by transcendar; to me these sound the best, not surprisingly I suppose. Enjoy and good luck!
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JBzen
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Re: Building a SE84 clone
Reply #3 - 02/09/22 at 21:04:48
 
Yes OPT is the final link in an amp like the amp is to the system. Steve definitely over built these amps and chose to forgo getting every once of power from the parts. The amps purr like a kitten and convey the same comfort as petting one.

I entertained the thought of getting Transcendar to wind a couple out of silver. Then looking at the latest prices of 5n silver wire quickly change that route. Prices have went up 50 percent in a year.

Thanks for your input on the different OPTs you tried Bobc. I figured a 5 watter should do well as long as it is not pushed too hard. I usally listen around the 12 oclock position.

John

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JBzen
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Re: Building a SE84 clone
Reply #4 - 02/10/22 at 15:29:19
 
Most of the parts will be here today. I dragged my butt from the Charoit and cut and filed the chassis top plate. Should have packed my micrometer when picking a drop from the tin shop. Ended up with 17 gauge. It will do.




John
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JBzen
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Re: Building a SE84 clone
Reply #5 - 02/10/22 at 19:04:32
 

The base has been assembled, glued, and clamped. The base will serve two purposes. One, as a platform to assemble the circuits. Two, as a finished base for the completed amp.

John
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JBzen
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Re: Building a SE84 clone
Reply #6 - 02/10/22 at 20:53:07
 


Stiff Miller time! Three packages came just as I installed the last screw on the plate. These contain the trannies and all the parts to lay out the plate tomorrow. Two more are in transit mainly resistors and should be here by Saturday.

Cheers!

John
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JBzen
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Re: Building a SE84 clone
Reply #7 - 02/12/22 at 19:16:53
 
Yesterday was layout day. Today drilling, cutting, grinding, and finishing the steel plate. Tommorow the parts will be mounted and a plan of attack created.


John
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JBzen
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Re: Building a SE84 clone
Reply #8 - 02/14/22 at 03:00:50
 
Time limited today but got the power transformer wired. Might get her heated up tomorrow.
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AMC CD8b>XO3>Cambridge CXN2>ZDAC>ZBOX>braided silver/occ> Zrock2>CSP2+>SE84 milflex copper 25th>9AWG silver/copper braid>lii Crystal 10 in Huijgen cabinets. Ortofon 2M Black>JVC QL-F4/Otari MX5050B2>ZP3. Isolation. AC filtering. Room treatment.
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JBzen
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Re: Building a SE84 clone
Reply #9 - 02/14/22 at 17:26:59
 


Things are going to get tight as can be seen by the preview pic above.




Got this far. Will definitely have to power her up before a 25th anniversary mod is applied!

John

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JBzen
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Re: Building a SE84 clone
Reply #10 - 02/15/22 at 00:41:23
 


Let there be light! Still got of lot to do but at least it is running.

John
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Lin
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Re: Building a SE84 clone
Reply #11 - 02/15/22 at 01:19:53
 
Curious why you turned the input tube?

Looks good.
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JBzen
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Re: Building a SE84 clone
Reply #12 - 02/15/22 at 01:53:42
 
Lin,

When I laid it out the OPs would not fit up in that area with the terminal lugs mounted on the side tube socket bolts. Turning the socket 90 degrees made it work. Still tight up there.

John
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JBzen
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Re: Building a SE84 clone
Reply #13 - 02/16/22 at 00:28:01
 


I use a set of old kiosk 8 ohm speakers(info commercial tvs used in retail stores the turn of this century) to test equipment. Last night there was a hum present that was mostly fixed by some wire and capacitor adjustment. This morning the phone was plugged in and all seemed good. Considering the power output of the phone and small 15 watt speakers volume was low. Took her into the Chariot this afternoon and was instantly amazed at the increase of soundstage. Almost overwhelming. Everything seem to be good, but after 20 minutes or so things started going south. Some distortion was starting on the right then the left further increasing to the point I jumped up and switched it off. Took her back in the shop to find everything was OK. No burnt resistors, visible shorts, solder joints look fine. Hmmmm! Hooked up the phone/speakers again and all sounded fine. Hook it back up to the Crystals and same distortion was present. Tried different tubes. No change. Turned the CSP2 volume down low and all sounded good again. By now it is starting to hit me that the transformers are not up to the task when the Crystals are yanking on SE84. So, I hooked up my Pyramid HT speakers and now the room is full of distortion free music. But sadly not sounding like the ZKIT/Crystals.
Well the lightweight transformers did the intended job of confirming the operation of the clone. The case can be finished. Be best to wait until I aquire some new trannies before installing the anniversary mods. Be nice if some UFOs slid into the mail box Cheesy. In reality, this will give me some time to study up on laminated trannies and possibly build my own.

John
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JBzen
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Re: Building a SE84 clone
Reply #14 - 02/18/22 at 09:38:37
 
Want to share one more observation. I used 40uf caps in the pi filter and sure enough the China made rectifier started bucking sparks at start-up. Changed it to a NOS RCA and no more sparks. So it seems the modern made rectifiers are no where near as strong or tolerance is a wee bit lax.

John
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bobc
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Re: Building a SE84 clone
Reply #15 - 02/18/22 at 13:32:51
 
Hey, thought I'd share my version. I was messing around and driving my B&W 702 with the clone. the watts there are are very sweet, and the amp deals well with the complex impedance. Windows aren't rattling, but ~85db peak.

Impressive metal and wood work!

I had the plate laser cut and had a friend help with the frame from repurposed picture frame.

I eliminated the 3.3uf divider network on the preamp power, and used 2x56k resistors. Also 47uf in the power supply. 6.5K custom transcendar opt.

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amp_001.jpg
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Lin
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Re: Building a SE84 clone
Reply #16 - 02/18/22 at 14:53:18
 
bobc wrote on 02/18/22 at 13:32:51:
Hey, thought I'd share my version.

I had the plate laser cut and had a friend help with the frame from repurposed picture frame.

6.5K custom Transcendar opt.



Very nice, I like the size. Cool
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JBzen
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Re: Building a SE84 clone
Reply #17 - 02/18/22 at 18:17:03
 
Yes, very nice Bob. I like the reclaimed picture frame base. I was thinking of a stainless plate but decided against it because it is very hard to drill. Laser cut is the way to go. Kind of wish my was wider but keeping to Decware size will fit into the scheme of things around here.

Is Transcendar still in business? I called but just get a number disconnected message. I see Edcor orders are pushed forward into June. Might just swap out trannies and keep looking.
I put in the Miflex oil coupling caps and the amp sounds pretty damn good right off the bat. Bass is a little flabby highs are crisp.



John

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bobc
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Re: Building a SE84 clone
Reply #18 - 02/18/22 at 19:19:26
 
Transcendar is no more.....biggest challenge of building tube amps these days is the supply of good opt.
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Ericus Rex
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Re: Building a SE84 clone
Reply #19 - 02/20/22 at 03:04:35
 
Super nice, John!

Too bad those OPTs didn't work out.  I'm thinking I'll have to get all my ducks in a row and order a couple of handfuls of Edcors for all the projects I'm planning.  Sure, I'll have to wait at first, but then I'll already have the rest on hand.

Do you know if the Hazen mod has any ill effects on tubes with an internal connection between supressor and cathode (EL84, 6P14P)?

I've ordered the parts for the 100R/330R conversion.  It will be interesting to hear the differences.

I'm looking forward to hearing more about your build!
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JBzen
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Re: Building a SE84 clone
Reply #20 - 02/20/22 at 11:23:43
 
Yesterday was one of those days that I thought it was going to be a tough start. Well to my surprise it went well at first and then almost ended in a fit of Smiley rage.

Listening to the clone the day before with the Zkit Edcore OPTs pushed me with some hesitation too pull the kit trannies. The kit was mature and sounding it's best. But, I really did not want to wait 3 months to hear a full modded clone. Proceeding with caution a plan was set.

Knowing that the coil covers would need removed to fit the trannies in the case of the clone created a cause for concern. A new mounting scheme would need to be created. The  factory metal covers serve a couple of purposes including built-in mounting feet. When the tranny is built all the laminating pieces are insulated from each other for it to work efficiently. So, I took care when making/installing u-brackets to keep the lamination of steel isolated from the chassis and its individual plates.



To make a long story short I failed Undecided

Never giving up and consuming the rest of a long day with a few trips between shop and z Chariot, a fix was created that will forge a path to a full blown anniversary modded clone.


Smiley
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JBzen
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Re: Building a SE84 clone
Reply #21 - 02/20/22 at 12:12:56
 
One more note to share. There was always a slight hum in the zkit. You know, hum that can be heard until music starts playing. Removing the Edcor covers made that hum completely go away! I really think that steel screws running thru the laminations is the reason. Not sure why but will ponder on it.

Thanks for the kind words Bobc, Lin, and Rex.

John
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JBzen
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Re: Building a SE84 clone
Reply #22 - 02/20/22 at 14:52:07
 
Ericus Rex,

I am running 1k grids with 100 ohm cathode resistor. Switched it out from the 150 ohm CR because the light weight OPT’s were having issues with it. Will have to try putting the 150 back in with Edcors running.

I really don’t think there will be any issue shorting the cap out on the suppressor with the 84s. Tube rollers do it all the time. I think Steve made it a permanent thing in all his SE84 builds. I think even tough it is bypassed in the tube, the cap still invokes noise suppression with the bounce back.

John
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JBzen
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Re: Building a SE84 clone
Reply #23 - 02/20/22 at 17:31:35
 
One of these days I am going to keep a written log of what is done during a project one of these days....

Changing the cathode resister to 150 ohm instantly increased volume and weight so much so that lead 🎸 riffs are utterly amazing!

One of these days...one of these days Smiley

Thanks

John
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JBzen
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Re: Building a SE84 clone
Reply #24 - 02/20/22 at 17:58:09
 


Found these on ebay. Should go well with the Tiny Radials and zkit for office use. On the way Smiley
One bad day deserves a good one for every boy. Just having so much fun today. Bet you can tell!
John
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galtjunk
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Re: Building a SE84 clone
Reply #25 - 02/21/22 at 15:24:51
 
So you changed your grids from 1k to 150r and really like the change?
My zen is in my office pushing a pair of tiny radials, so I don't sling solder on it much anymore.
It seems plenty loud now as it is.
I may consider it when I do the anniversary upgrades.
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JBzen
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Re: Building a SE84 clone
Reply #26 - 02/21/22 at 15:58:55
 
Galtjunk,

Thanks for pointing that out. The common cathode resistor was changed not the grid resistors.

Sorry about the confusion. I edited it above.

John
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JBzen
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Re: Building a SE84 clone
Reply #27 - 02/22/22 at 03:14:46
 
[size=20][/size]This morning the anniversary mods were added.


The case will be about 2 3/4" high when finished. About a 1/4" higher then the rest of my Decware equipment.



I have but 5 hours with anniversary mods 10 total since the amp came to life. It sounds very good and will get better with time. Tomorrow I will finish the cabinet.

John
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bobc
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Re: Building a SE84 clone
Reply #28 - 02/22/22 at 13:41:33
 
Looking great! Regarding your hum, did you measure the hum in mv at the speaker terminals? And the 150ohm resistor sounds better for sure, changing that resistor also significantly changes B+. For fun, in a "junk build" I put the resistor on a switch for a build so I could a/b the change.

The hazen mod can be applied and the amp run EL84. It has no effect because those pins are shorted internally in the tube. I also played around with 330ohm on the grid resistors vs. 1K; I liked the 330ohm better.

Another "add" you can do is put a switch on the UL transformer tap (blue white wire). You bypass the 1K triode strap resistor on the output tube and run the UL tap to this point. You get a titch more power from the amp because it's running in pentode mode, and can switch to "default/triode". Hate seeing the UL tap go unused....

Interesting about the transformer bells and hum.

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Lin
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Re: Building a SE84 clone
Reply #29 - 02/22/22 at 14:51:20
 
bobc,

But now to be fair to pentode you need to put in another switch for some type of feedback (Schade?). Smiley
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bobc
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Re: Building a SE84 clone
Reply #30 - 02/22/22 at 15:56:09
 
AFAIK You can just wire the blue/white lead to pin 9. Personally I prefer the triode strapped versions sound... Schade another discussion, but I hear you..

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JBzen
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Re: Building a SE84 clone
Reply #31 - 02/22/22 at 21:58:32
 
Got her done! 12 hours and the music is sounding new, different, wider, deeper, blacker, and detailed. Still a bit of strain in the high end, bass not as detailed as I became custom to with the Zkit. It will all come around in time. Guess all I have to do is play music! Yeah right, next up isolation platform reorganization which will involve shoptime. Then some of Steve's TRs for the office.




John
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Geno
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Without music, life
would be a mistake.

Posts: 2149
Re: Building a SE84 clone
Reply #32 - 02/22/22 at 22:08:55
 
Hi John. It has been fascinating (as a non-DIY guy) to follow your progress with this.

This is the first time I've looked at the photos on my PC instead of my iphone. Glad I did, because I can see the detail so much better. Just beautiful!

Thanks for posting!

Best,

Geno
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(2)SE84UFO(Balanced Monoblocs) OR Sansui AU222
Cambrge Audio CXN(ModWright)
Crown XLS-1002
SL1210MK5(KAB Mods) Soundsm Aida MKll cart • Darlingt.Labs MP8b
Otari MX5050-Bll2 R2R
ZLC Power Cond
Lii Audio PT-10 OR F-12 OR Betsy Alnico 8"/ W-15 in Open Baffle
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JBzen
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Re: Building a SE84 clone
Reply #33 - 02/23/22 at 01:09:40
 
Thanks Geno! Happy to hear it looks good on the PC. I used the phone camera. Almost got the SLR out.

Bobc I did not check voltages on the outputs. Did a B+ check and it was under 300v with the 100 ohm resistor. I might add front inputs for the purist approach.
About the transformer, bolts thru the laminations were rubbing the first lamination that pinched the thread because it was not lined up correctly. When reinserting the bolts, I may have shorted a few more laminations which caused quick saturation with music playing. In short the Edcors sounded like the 5 watters. I just pulled the bolts and all is well with a no hum bonus!

John
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Ericus Rex
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Re: Building a SE84 clone
Reply #34 - 02/23/22 at 03:22:49
 
Interesting r.e. the steel screws...maybe a non-ferrous screw would do the trick and be a bit more secure than the zip ties?

Very nice job!!
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JBzen
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Re: Building a SE84 clone
Reply #35 - 02/24/22 at 02:25:59
 
I had a plan for this morning of rearranging the bookshelf in the office putting a few things away to make room for the Zkit. Woke up at 1:30 am...yes just about last call at the local taverns...and had SE84 on my mind. I went downstairs without even starting the morning coffee pot. Turned on the clone and listened 5 straight hours! Spent last evening doing the same 5 hour shift. Why? Well the system sounds different with the clone. There is more detail in the midrange for sure, more throat sounds from singers, sharp notes off of string instruments, sharp piecing notes coming from throats of horns, drums are room filling, and on and on. But, there was this nagging thing that most likely got me out of bed and down the steps without blinking-a-eye. Vocals were not right. There seem to be a nagging sibilance from time to time. Not the Sssssss associated with a hot mike but more like the type of distortion one would hear on worn vinyl. The hiss of splutter. It did not occur all the time but it did occur often enough to get my attention. It was still there this morning. What could be causing this I wondered. The vocals were always clear on the Zkit.

So the more it happened the more I dwelled on it thinking did the Hazen mod caps get too much heat? After all this is the second go around for the .01uf caps use coming from the Zkit after the anniversary couple caps upgrade. The leads are short after being used on the circuit board and it took some finagling to get it soldered up. Nope, probably not I thought. Maybe the input 1K grid resistor added for some reason. I do not know why but it was put in! A volume control was not needed because the CSP2+ will do that work. Could it be that foot long low noise cable I repurpose from the ZP3 that someone left in the case after moving the inputs to the front of the chassis. Very possibly! I also notice the clone seemed kind of veiled, on the dim side, missing vibrancy which I was blaming on breaking in issues. It has been 22 hours now and the bass was starting to tighten a bit and high end was getting less edgy. The sibilance was not letting up and the veil was ever present. What could be going on here?

The ah-ha moment finally came after a short sleep coffee less morning. It would be the fix for sure. It had too be. First that 1K grid resistor had to go. It is not needed and must be adding its signature to the music. Second, I have 4' of 5n 22 gauge silver in the coiffeurs left over from the interconnects built last spring. The silver wire can replace the low noise 2 conductor copper shielded cable. I got a plan!

At this point feeling the pain of not eating breakfast, sleep deprivation, and no coffee fix, I took care of these issues before finding all that would be needed to get this clone singing a tune. Feeling somewhat rejuvenated I set out to assemble the silver cable with some salvaged copper shielding, teflon tubing, and clear shrink tubing. The clone has a silver plated copper ground buss from the mains ground all the way up to the input tube area so an addition ground wire was not needed in the cable. The silver wire was threaded thru teflon tubing twice and the resulting two wire assemblies were threaded thru the copper braded shield. The cable was then inserted into the shrink tubing. The 1k resistors were removed with one end of the new cable soldered to the input tube socket pins. The shield was cut back about an inch and sealed in the shrink tubing. The other end was connected to the input jacks with the braiding attached to the inputs ground. Shrink tubing will be heated and job complete.



More to come because it did not go well for me but great for the clone.
Hint, both pics show obvious errors. Can you find them?


John

PS
Thanks Rex!
 
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AMC CD8b>XO3>Cambridge CXN2>ZDAC>ZBOX>braided silver/occ> Zrock2>CSP2+>SE84 milflex copper 25th>9AWG silver/copper braid>lii Crystal 10 in Huijgen cabinets. Ortofon 2M Black>JVC QL-F4/Otari MX5050B2>ZP3. Isolation. AC filtering. Room treatment.
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diybill
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Re: Building a SE84 clone
Reply #36 - 02/25/22 at 21:29:30
 
Hi bob I recently bought all the parts to make a se84 clone . I have searched the DECWARE forums  with every combination I can think of, for a schematic or description; that lays out the meter circuit.  I see that your build has meters. Any insight that  might help would be greatly appreciated'


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bobc
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Re: Building a SE84 clone
Reply #37 - 02/26/22 at 13:40:18
 
Wiring is easy.

Finding something looks good and is "right" is harder. in the MA range. These are cheap Chinese eBay that work. Ideally I wanted something higher end.

You can switch them in / out, or wire in with the cathode resistor.

These are 100MA meters that have 2 ohm resistor across terminals. So my cathode value is actually 152 as they are wired in line. The meters have a coil too, which in theory may affect sound too. I listened both ways, the meters did not affect sound to my ears. Wire meter between resistor to ground, and the bypass cap directly to ground.

You can switch in a 100mv meter across a 1ohm resistor.. In this case mv=ma. Cathode bias is 151 in this case. Wire this same way, at the "bottom" of the resistor. You can also do this with "any" meter, ohms law and math, by shunting a resistor across the meter to change its range. Check out the 25th thread for some pics, you can see this amp has a shunt resistor across the meter.

They are very useful. I know immediately if I bought a bad output tube, or something funky in the input stage tube. Meter indirectly reflects B+ value as a higher B+ (say a solid state rectifier, line voltage or whatever) results in higher bias current.

NOTE: ALSO despite what I typed to illustrate bias resistor value if you want to do separate bias and meters for each output type use a 300R resistor (2x150) bypassed with 1000uf. You can do this with or without a meter if you think that this is "better" (some say it is).

I just finished up a 300B amp, and I used a switch, cut the internal resistor and switched the meter across some 2ohm power resistors I put in series with the "main" cathode resistor. Middle is off, left - left tube etc. So in both cases my cathode bias is a few ohms off (call it tolerance).

You can see the amp clip when the meters move. These meters  dont "dance" just sag a little to confirm what your ears hear.

There are some very high cost "audio" MA meter you can use too. Yamamoto makes one I think. Was looking at Simpson meters too, but many of these meter companies seem to be OEM oriented. My cheap meters work, a high end jeweled movement with ballistics would satisfy my soul, but I dont think would affect function or sound one way or another.

I hope all this made sense.

Good luck.
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Crazy Bill the Eel Killer
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Re: Building a SE84 clone
Reply #38 - 02/26/22 at 16:30:29
 
Bob is right on the Yamamoto meters.
Just to whet your appetite:

http://www.jacmusic.com/Yamamoto/meters/index.html
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Archie
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Re: Building a SE84 clone
Reply #39 - 02/26/22 at 16:44:23
 
Wow, those are nice!  Any idea where to get them or how much they cost?  The ZMA meters are the standard all plastic cheapo kind seen everywhere.  Assuming the Yamamoto don't cost more than the amp, they'd be a great upgrade.   Smiley
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Crazy Bill the Eel Killer
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Tubes Rule !!

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Re: Building a SE84 clone
Reply #40 - 02/26/22 at 17:34:00
 
You can get them from JACMusic. The page shown is from his website.

Go on his website and there is a pricelist that covers everything on his site. Bit of a pain to navigate, but you will find it.

That is a German site. I have bought many things from JAC over the years with no issues.

I would think George Lenz at TubesUSA would also be able to get them for you, as he is an authorized Yamamoto dealer, as is JAC. Neighbor of mine just above NYC. Completely reliable and a good guy to boot.

Cheers,     Crazy Bill
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Archie
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Re: Building a SE84 clone
Reply #41 - 02/26/22 at 18:04:40
 
Thanks.  I emailed for a quote but then I did some measuring of my current meters and they are bigger.  So, no go.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Gmidstokke
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Re: Building a SE84 clone
Reply #42 - 02/27/22 at 01:33:27
 
Do you think there would be an audible difference if you used the same tubes with this and a real Decware? Really fun build to read through.

I have yet to get blown away by a reference system in person.
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JBzen
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Re: Building a SE84 clone
Reply #43 - 02/28/22 at 11:56:37
 
Gmidstokke,

I've been blown away with mine at times with the right material. My biggest fear is getting totally wrecked after visiting Decware in Peoria someday!

John
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AMC CD8b>XO3>Cambridge CXN2>ZDAC>ZBOX>braided silver/occ> Zrock2>CSP2+>SE84 milflex copper 25th>9AWG silver/copper braid>lii Crystal 10 in Huijgen cabinets. Ortofon 2M Black>JVC QL-F4/Otari MX5050B2>ZP3. Isolation. AC filtering. Room treatment.
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JBzen
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Re: Building a SE84 clone
Reply #44 - 02/28/22 at 13:33:49
 
I asked a question above about obvious errors on the preceding two photos. Did anyone see any? Of course it is easy for me to see because I made and corrected those fupas. I will point them out this post and add a couple.

The pic below circles the areas that were corrected in green. Starting from the top left's green circle the common output tube cathode capacitor is an electrolytic 1000uf that IS installed correctly with + oriented toward the cathode. When I replaced the strapped 100 ohm resistor with a 150 ohm it was placed in reverse as shown in the picture in question blowing the cap.

The middle circled circuit is a bonus addition of a snubber circuit given to me by the audio god's disciple while eating a late dinner and browsing. This circuit separates the audio ground from chassis ground. This helps to eliminate more background noise. It helped the clone even further reduce a faint buzz after what the OP tranny observation with screws played on hum.

The bottom circled input cable connection shows the correct way to install a shield provided by the made up cable. The shield is connected to both grounds of the inputs and floating at the outer end(cut short about an inch from the input tubes cathodes and sealed inside the outer layer of the cable). As shown in the questioned pic wrapping the silver wire around the two insulated conductors in that fashion created an antenna that basically picks up all the noise in the clone's circuits. When it was powered up the hiss was loud and the amp started oscillating in short order. When I was making the cable there was 2' of silver wire left so I though why not. Wrong!



So again I answered my questions with more questions that leads too good success Shocked The pics below expand on the metal covers removal from the Edcor recommend output trannies of the Zkit1 that were installed in my kit and used in the clone. Edcor does not heavy coat trannies with lacquer that are destined for the bell covers. The coating can be easily nicked even with careful handling unlike the transformers without covers that have a heavy coat and protective metal cover on the perimeter of laminations. As can be seen in this pic the circled part of the lamination corner edged has a slight scraping. It was most likely caused from rubbing the deburred edge of the clone's top plate while I was trying to figure out a mounting scheme. So it don't take much to mar the soft laminations!



This magnified pic shows the bridging of laminations that resulted. This little slight short caused the otherwise stable Edcors to saturate very easily when the right channel Crystal speaker started to impose its own impedance.



I used a brass brush to work the shorted bridge out as seen below.



I now have 35 hours music playing time on the clone. It just keeps improving. I am starting to pick up errors on CDs never noticed before. Kind of like time slows down and those errors are given more time to show. In reality, the errors are expanding nuances on themselves with the clone. Meaning, when played back on a phone with headphones and knowing where to look the error is a quick blip that is hardly noticeable.

Did Steve go too far with the anniversary? Nope Smiley

John

 
 
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AMC CD8b>XO3>Cambridge CXN2>ZDAC>ZBOX>braided silver/occ> Zrock2>CSP2+>SE84 milflex copper 25th>9AWG silver/copper braid>lii Crystal 10 in Huijgen cabinets. Ortofon 2M Black>JVC QL-F4/Otari MX5050B2>ZP3. Isolation. AC filtering. Room treatment.
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