Just thought I'd start a build thread if anyone is interested. You Gurus may also be able to spot stupid problems with my pictures probably. =)
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Dec 18.
All parts have arrived from Digikey. Tubes are here already. Sovtek KT-88's Chinese 12AT7 and 5AR4's. (Yes, I'm on a budget). All tube sockets are ceramic and gold plated.
Power transformer is the Allied 6K7VG
OPT's are Hammonds 125-CSE
Both are on order
gold plated binding posts, ac plug with "line filter", and hopefully neutrik RCA jacks are comming in soon.
There is no planned choke or supplemental power capacitor. Also no pot, no FRED's, and no enclosure so far.
The amp will be powering 2 Dahlquist 8Ohm bookshelf speakers, 6 inch woofer with 1 inch tweeters.
Pretty busy so far, but I hope to start soldering by tomorrow. Pics will start when the project starts =)
Total cost so far (CND)? 268 paid and expecting another 150 for the transformers. broke already =(
Question for the pros -- what would happen if I used the R1 resistor to limit noise and then also added a choke later without desoldering it?
If this type of thread is prohibited please lock and delete.
Dec 18.
All parts have arrived from Digikey. Tubes are here already. Sovtek KT-88's Chinese 12AT7 and 5AR4's. (Yes, I'm on a budget). All tube sockets are ceramic and gold plated.
Power transformer is the Allied 6K7VG
OPT's are Hammonds 125-CSE
Both are on order
gold plated binding posts, ac plug with "line filter", and hopefully neutrik RCA jacks are comming in soon.
There is no planned choke or supplemental power capacitor. Also no pot, no FRED's, and no enclosure so far.
The amp will be powering 2 Dahlquist 8Ohm bookshelf speakers, 6 inch woofer with 1 inch tweeters.
Pretty busy so far, but I hope to start soldering by tomorrow. Pics will start when the project starts =)
Total cost so far (CND)? 268 paid and expecting another 150 for the transformers. broke already =(
Question for the pros -- what would happen if I used the R1 resistor to limit noise and then also added a choke later without desoldering it?
I see lots of gold plated parts in your list. I've been told that it is best to scrape or sand the plating off the part where you make a solder connection. Otherwise the solder will stick great to the gold plating, but five years later the plating will 'peel' off the part and you'll get a lousy connection.
If you opt to use R1 instead of a choke, you'll have more 120Hz ripple on the B+ supply. You may hear a faint hum from the speakers if they are efficient ones. Given the description of your speakers and their "bookshelf" nature, I'd be tempted to try it without the choke and see if it is a problem. If you choose to add a choke later, you need to snip out R1 or you won't get the benefit of the choke.
If you opt to use R1 instead of a choke, you'll have more 120Hz ripple on the B+ supply. You may hear a faint hum from the speakers if they are efficient ones. Given the description of your speakers and their "bookshelf" nature, I'd be tempted to try it without the choke and see if it is a problem. If you choose to add a choke later, you need to snip out R1 or you won't get the benefit of the choke.
Hey Thanks for the Reply,
The gold plated is the female side of the socket, the end that connects to the PCB isn't plated =)
And the news regarding the choke is a good news. saves me $$$. I'll remember to post results when I finally get it built. If there is hum it should be evident since I dont have pots right?
The gold plated is the female side of the socket, the end that connects to the PCB isn't plated =)
And the news regarding the choke is a good news. saves me $$$. I'll remember to post results when I finally get it built. If there is hum it should be evident since I dont have pots right?
I assume you've already ordered and received your power transformer from Allied. If not, the C-14X is a recommended choke for the Simple SE and costs a little over fifteen dollars. The C-24X is even cheaper; just under eight dollars. George used a C-24X in his "industrial" amplifier. I believe even a small filter choke is better than none at all.
Of course, if you have the resistor it doesn't hurt to try it and see if it works for you. You can always add the choke later.
Of course, if you have the resistor it doesn't hurt to try it and see if it works for you. You can always add the choke later.
With voltages around 450vdc, you or some other curious fingers could get seriously hurt. Try dumpster diving for a broken integrated reciever and gut it for it's chassis. A cake pan may also be used. Be sure it doesn't have any cake in it though.
I would guess cutting holes would be a challenge though without the right tools.
Yes, even the $6 choke is measurably better than a resistor, but I can hear no difference on my 87db Yamaha monitor speakers which are a bit weak in the bass response. I can hear the difference on my big 96db speakers. The choke can always be added later if hum turns out to be a problem.
The cheap punch set from Harbor Freight works good, but the hole sizes are not optimum. Thin material like a cake pan can often be drilled using a cheap spade bit set, or even a hole saw. You need to clamp a sacrificial piece of wood to the back of the metal to avoid tearing the metal. I have even used the drill a few 3/8 inch holes and file or Dremel to fit method. It works good if you have a large supply of patience. Unfortonately, I don't.
I agree that some type of enclosure is needed to protect users, friends, and pets from 450 volts. Death is permanent and very possible. Ultra low tech and cheap, mount it all on a piece of wood and put a cage over it. I have used the stainless steel mesh trash cans or DVD cases from Target or Walmart. The cage MUST be grounded to the green wire on the power cord.
whitelabrat said:
The right tool makes any job easier.
The "step" drills at harbor freight make nice holes in any material thinner than the depth of the steps. The were just the ticket for drilling the larger holes in the sheet of 1/8" T6 I'm using for my Simple SE chassis. I used my cheap-o Chinese drill press for most of them, but a steady hand and a low speed on a hand-held drill were just fine for the rest.
I'm a big fan of the Harbor Fright step drills, especially if you are drilling aluminum. They make nice smooth holes, even in 3mm thick stuff. I've been told that a "good" chassis punch is even better, but good chassis punches cost good money.
I bought the three piece step drill set, but it only goes up to 1/2". I'd recommend going for the two piece set that makes holes as big as 1-3/8".
A cheap press stand helps a lot, too.
I bought the three piece step drill set, but it only goes up to 1/2". I'd recommend going for the two piece set that makes holes as big as 1-3/8".
A cheap press stand helps a lot, too.
I finally got started! all went well with the resistors i think. Here are a couple pictures.
Note my old school pencil iron. Got my dad through school too =)
edit. always says my pictures are too big! i thought 102400bytes is 800kb? my photos are resized to 400 already. I will try to figure it out later when I return!
Note my old school pencil iron. Got my dad through school too =)
edit. always says my pictures are too big! i thought 102400bytes is 800kb? my photos are resized to 400 already. I will try to figure it out later when I return!
First, apologize to nukaidee for thread jacking a little OT but not totally off base
I bought a fully populated SimpleSE board, PT, and Choke from another member John, but I was too late to buy his OT's. I have a pair Hammond 1627SEA OT's. However, the primary impedance is 2500. Unfortunately, the speakers that I intend to use are 4 ohms. If they were 8 ohms, I could wire them to the 4 ohm tap to reflect a 5K load on the primary. So, the question is, are 2500 too low or I shall look for something higher? Another question is, John has the components soldered on the top of the board, will it be a good idea to desolder the components and mount them on the other side (which I prefer)? My fear is that I may overheat the components while doing so.
I bought a fully populated SimpleSE board, PT, and Choke from another member John, but I was too late to buy his OT's. I have a pair Hammond 1627SEA OT's. However, the primary impedance is 2500. Unfortunately, the speakers that I intend to use are 4 ohms. If they were 8 ohms, I could wire them to the 4 ohm tap to reflect a 5K load on the primary. So, the question is, are 2500 too low or I shall look for something higher? Another question is, John has the components soldered on the top of the board, will it be a good idea to desolder the components and mount them on the other side (which I prefer)? My fear is that I may overheat the components while doing so.
Yup, I've got a Greenlee punch that is the perfect size for Neutrik D-size housings (their xlrs and even some rcas) and it has more than paid for itself now in saving both time and aggravation. But even cheap chassis punches can come in handy. I bought a set from HF a couple years ago and used them for the first time on my recent SimpleSE build. Turned out that what they called a 1" punch was the perfect size for the octal sockets that I used. Granted I still had to drill a 3/4" pilot hole for the punch but I've got a set of 3 Irwin stepped bits that includes one that goes up that large so it was no trouble. Drilling difficulty strikes me as an exponential relationship compared to hole size. Even then I've had pretty good luck with bi-metal holesaws once the hole diameter is over an inch. I have also had really bad luck trying to use stepped bits at hole diameters anywhere over an inch, and yes that is using a drill press and clamps. They just aren't made for precise work so they tend to not cut round holes.Ty_Bower said:
That's my 2c,
Nate
I've got the Harbor Fright plumbers' chassis punch set. The little one is too small for anything, and the two biggest ones are too big. The only one left is fairly large for a noval socket, but OK as long as you don't mind the gap. It's really tight for an octal socket, and you've got to be lucky to get it to line up in the right spot. I managed to punch ten holes with mine before I got a piece jammed in the punch. In all fairness I am punching 3mm aluminum plate, which is clearly more than this punch was intended to handle.
I used the 1/2" step drill to make the pilot hole for the punch.
I used the 1/2" step drill to make the pilot hole for the punch.
another update! i still can't post pics, but all parts are soldered. my coupling capacitors are auricaps. the trasnformers are in town, but haven't been picked up yet. many threads talk about "testing" the amp before hooking it up to anything, I haven't figured out what I should be prodding with my multimeter. any suggestions?
thanks!
thanks!
For your photos, get a free account at Photobucket.com. Upload your photos, check the little box underneath them, and press the blue "Generate HTML and IMG code" button at the bottom of the page. Copy the code in the section titled "IMG clickable thumbnails for message boards - recommended" and paste it into your message here.
Did you figure out the sockets?
Pre-testing usually involves the ohmmeter and checking to make sure that nothing is shorted to ground where it should not be. You can also measure most (if not all) if the resistors while they are on the board and confirm they are the right value. I like to use a printed copy of George's parts list and check off each part as I verify it is correct. It's also a good idea to double check the electrolytic capacitors to ensure they are installed with the proper polarity.
Did you install the solid state FREDs? Recently there has been another report of trouble with them.
Did you figure out the sockets?
Pre-testing usually involves the ohmmeter and checking to make sure that nothing is shorted to ground where it should not be. You can also measure most (if not all) if the resistors while they are on the board and confirm they are the right value. I like to use a printed copy of George's parts list and check off each part as I verify it is correct. It's also a good idea to double check the electrolytic capacitors to ensure they are installed with the proper polarity.
Did you install the solid state FREDs? Recently there has been another report of trouble with them.
nukaidee, glad to hear you've got a chassis in the works. I used a Greenlee 1/2 and 3/4 conduit punch for the job, and a cheap hand drill for everything else. As far as testing I simply looked at everything closely to be sure everything was soldered correctly. And then I did it again. And again. Then I wired everything up and brought it up on a variac while cringing and hoping there would be no smoke.
I smoked a Sovtek 5ar4 yesterday after a year of service. Sparks and popping in the tube. I turned off the amp immediately and retired that tube. I've got a 5u4gb in right now cause I'm too busy to dig around for another 5ar4. The 5u4 it drops the voltage too much to sound ok but it's good enough for now.
I've got a set of FRED's I'm thinking I'll put back in. Having a CL90 thermistor (did Tubelab suggest a CL110?) and avoiding a standby switch should do just fine.
I smoked a Sovtek 5ar4 yesterday after a year of service. Sparks and popping in the tube. I turned off the amp immediately and retired that tube. I've got a 5u4gb in right now cause I'm too busy to dig around for another 5ar4. The 5u4 it drops the voltage too much to sound ok but it's good enough for now.
I've got a set of FRED's I'm thinking I'll put back in. Having a CL90 thermistor (did Tubelab suggest a CL110?) and avoiding a standby switch should do just fine.
another update!
sorry about the delay. My binding posts came in as my ac plugs. I also picked up the transformers. man! they're alot heavier than I'd have thought. I expected the allied ps to be the size of the hammonds and the hammonds to be half their size. I inspiration for an enclosure now they're much too big and heavy. My RCA jacks still aren't here yet either, so no input yet, I might to wire up a 3.5mm input for now since I have those lying around.
sorry about the delay. My binding posts came in as my ac plugs. I also picked up the transformers. man! they're alot heavier than I'd have thought. I expected the allied ps to be the size of the hammonds and the hammonds to be half their size. I inspiration for an enclosure now they're much too big and heavy. My RCA jacks still aren't here yet either, so no input yet, I might to wire up a 3.5mm input for now since I have those lying around.
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