I've been on a DIY bender since completing my first O2 some 6 months ago. My older brother and I built Heathkits during our teen years, and O2 (partly because of the intrigue surrounding it) provided the needed nudge. An O2 was followed by another O2, then a couple of CTH's (an awesome little amp by the way - Thanks Alex and Chris).
While looking around for my next project, I happened upon another hybrid tube amp called 'Project Sunrise' — designed by Frans and kitted by Jeremy of Garage 1217. While it was very similar to CTH (single triode hybrid, 6v/12v 9 pin tubes supported), I really like the clean open chassis design and its Class A output stage.
So I placed an order, and was immediately informed by Jeremy that Project Sunrise was EOL, and Project Sunrise II was just around the corner. The second edition of Project Sunrise retains the same sonic character as the first, but adds…
- Easy LED tube biasing.
- Improved on/off protection.
- Improved circuit layout.
- More goodness!
Excellent! My wait increased a bit, but for a few more dollars (disclosure - Jeremy gave me Project Sunrise II for the price of Sunrise) I get the new and improved Sunrise.
After one minor delay my kit arrived — which included a travel case and 1 6N23P tube. I was pleased to notice that I received 'K0001'. Not a big deal really, but kinda cool :-). While the 'end game' for any audio DIY kit is the sound, this review will focus on the kit and build. I'll post another review soon that will focus on the stellar sonics of this amp.
Unpacking the kit, I was immediately impressed by the quality of the PCB. Granted I haven't seen many, but this one's thicker with better traces and pads. According to Garage 1217, it's a "2 layer, black mask with gold wash circuit board / full lower and upper ground planes - .096 2OZ FR4 board!". Ok - It's all Greek to me, but it's the best I've worked with.
Beyond construction, the layout is symmetrical and well thought out. Pads are generous, with ample space between them. Component locations are clearly labeled, with orientation (where applicable) clearly indicated. One thing worth noting - Garage 1217 has designed this PCB to be used with both Project Sunrise and Project Horizon (a future 48v version of the same design). This results in a couple of component positions that need to be ignored or simply 'jumped'.
While the manual did give instructions as to which should be jumped, it was a bit confusing as I wasn't sure if the jumpers (wire) should be permanent or temporary — as is often done when you need to test specific circuits during startup. This is a good time to mention that Jeremy is a solid, friendly dude that's gone out of his way to provide the best possible experience with Project Sunrise and Garage 1217. As I worked through these minor issues, Jeremy was quick to provide the help needed — and often updated the manual to clarify what might be confusing to DIY rookies such as myself.
Back to the kit, which came well labeled with components in individual bags (anti-static when needed). Garage 1217 didn't cut corners with kit components — output caps are Nichicon FG's, resistors are Vishay RN series, pots and trimmers are Bourns; all audiophile grade components. Even with this Garage 1217 went a step further with a PCB designed to accept a wide variety of component pitches and diameters. Tweakers and tuners can go wild! When assembling, I found all components to be properly and clearly labeled. Nothing was missing, nothing was extra.
The mechanic aspects of the kit (chassis, top, etc.) were top notch. Honestly, the fit, finish and overall quality of the kit exceeded my expectations for a kit from such a small operation. Kudos!
As I discuss assembly, it may at times read like an addendum to the manual. This is somewhat deliberate, as I want to pass on details that may be helpful.
For the most part, the quality of 'kitting' and board layout places Sunrise II firmly in the beginner category if it wasn't for that one SMD (surface mount) component — an LED. Not that it's difficult to install — it just requires a steady hand with a bit of care to watch your soldering temperature. Because of this, I'd rate the kit as intermediate — though quite doable for beginners.
The manual begins with the usual (and appropriate) 24VDC danger warning. As with any electronic kit, damage and injury can occur if care isn't taken to insure proper safety. If you're a DIY 'newbie' and work slowly and deliberately — following the manual you shouldn't have any problems.
Actual work begins with PCB prep — the 90% Isopropyl Alcohol bath. If you're anything like me, you may be eager to skip this step and dive in. <strong>Don't do it!</strong> While the the kit PCB came relatively clean, solder will flow much better if you take the time to insure that the board is free of chemicals and oils.
Next up is heat-sink assembly and bottom chassis prep. When you've assembled your heat-sinks, set them aside such that the device leads are not bent, and will not be subject to static electricity. I rested mine on the anti-static bags the devices came in.
Component installation was straightforward and follows the common DIY axiom of 'small and low, first to go'. Ok, maybe I just made that up. Resistors, diodes, small caps and such first — followed by medium sized components and finally large. If the board layout allows, I like to install more sensitive components (those shipped in anti-static bags) last, regardless of size — just to be safe.
Be sure to ground the volume pot (per the manual). It's critical for quiet operation. While it's not discussed in the manual, I highly recommend another 90% Isopropyl Alcohol bath on the bottom of the PCB to remove the rosin. You may need a couple of passes to get all the rosin off, but it will extend the life of your circuitry.
Set the LED and input capacitor bypass jumper to default settings, and install the top acrylic panel.
Set output resistance jumpers to default settings, and set the tube heater voltage jumper accordingly to match the type of tube you'll be using. If you received a 6N23P from Garage 1217, set it to 6 V. Now insert your tube.
Power it up, and let it sit for a minute or two while you look for 'magic smoke'. If all goes well (and it usually does if you've followed the manual), you're ready to adjust the tube bias.
V2 of Project Sunrise has made this easy with a couple of small but significant enhancements:
- 'High/Low' voltage LED's allows adjustment without a meter.
- Tube bias trim pots are adjustable with the top in place.
Just follow the bias adjustment steps in the manual to dial in the bias for both left and right channels. If you're 'old school', there's a page covering tube bias using a meter.
For the sake of disclosure, I did come across a couple of minor issues during the build — though some fall squarely in the realm of 'builder error':
- A couple of components were miss-labeled in the manual.
- A couple of jumpers (IC1) seemed temporary, when they needed to be soldered.
- There's a couple of redundant 'JP2' pads that I accidentally installed my jumper pins in.
- A couple of my standoffs cross-threaded the first time I removed and reinstalled them.
All of the above have been corrected by Garage 1217 through manual changes or parts replacements. Through the entire build, Jeremy was quick to respond and correct everything I found. But he went even further — after building I noticed a very slight low volume channel imbalance. I didn't mention it to Jeremy as I never listen to music that low, and it evened with the slightest volume increase. Jeremy notified me that a small number of pots had this imbalance, and he was sending out a replacement. Now that's service!
All in all, Project Sunrise II was a very enjoyable kit to assemble. Fit and finish was top notch, quality parts are provided throughout, and the instruction manual is clear and well written. If you're a beginner with a kit or two under your belt (or a beginner with help available if needed), I highly recommend you give Project Sunrise II a try.
Feel free to ask any questions you have about this kit - I'll do my best to answer them.