Cost to build 45/2A3 SET int amp

Just wondering how much will it be if done by local diy job. No need high end. I am on the budget.

Hi Hasnul, that is a very tough question, but I personally think that a 2a3/45 DIY can be less than RM 1,000 on a really conscious budget; but I would plan for upto RM 2,000 for a decent diy unit with "better" parts options. But then for the money, you may consider a made-in-China product or a used item - less fuss, risk and agro.

I have personally DIYed two 300b monoblocks based on JE Labs 300b and WE 91A schematics. I initially planned for a RM 3K budget stereo but ended-up with a monoblock pair. It ended up to more than double the budget when I started "upgrading" using branded parts - Audio Note 2W resistors, Riken resistors, DALE power resistors, mundorf silver-gold oil, obbligato film oil for PSU, Sophia OPT, Shuguang Treasures 300B-Z, RCA NOS 5U4G rectifiers, Prometheus Audio power transformer&inductors, etc. After about 150hr of use, I am quite pleased with the results.

The most expensive items are the tubes (especially the 2A3/45) and the output transformers. That may cost you upto 2/3 of the total cost. The remaining cost of parts are for the capacitors and passive devices.

For a budget less than RM 1,000, you would need to personally handle the soldering iron and carpentry for the box. The PSU would use 500VDC electrolytes and solid stage rectifiers, made-in-China tubes, generic output transformer (via e-bay or salvage) and Pasar Rd power transformer (or salvage). The passive devices would not cost much but budget for a high-quality signal-path capacitor.

If you need assistance, PM me as I am planning to DIY either a 45 tube-amp or a 845 tube-amp project in the near future.

Hi mthoi, I'm also interested in diy a 2a3/45 amp. A pair of decent 45 tube cost more RM 1k. Would also planing to use black gate NH in super E-cap in the power section n cathode by pass. Now I'm still looking for suitable schematic. Preferably with interstage trans.

pm sent.

I got my kit for about RM5k complete with mega sized Tamuras and NOS tubes and regulator. The transformers make a world of a difference. You actually get what you pay for.

Noodle - there are a fair number of schematics on the internet. Take a look at www.vt52.com for a 45 project that uses Tango iron for the interstage and output. The parts counts are also minimal. These "no longer in production parts" are all hard to come by and fetches premium.

I am considering a Shishindo-based Loftin-White 12ax7/45 schematics that is without interstage and coupling cap. PM me if there are any interests in joint DIY.

Brabusm have a nice budget for a DIY 45 at RM 5K. That would be a good budget for a serious DIY using premium parts.

DIY can be on the "cheap" or can be as costly as any commercial product, if not more. Eitherway, the joy of building something and getting it to work are priceless.

As Hoi said the budget can vary from RM 1k-5-6k.

If u can diy all by yourself including the casing then at RM2K can get a boleh tahan’s equipment la.



Circuit wise they are plenty, for limited budger normally go for Direct couple / cap couple. You can use the those ready circuit in web or u r adventure enough, u can do like me to use whatever tube I like as driver tube & input tube, as long as u bias it correctly, not over load it too much it will work and sing.



Some estimation for parts:



5k OPT- colin ~rm300+, SAC ~rm 700+ , hashimoto ~rm1.5k



45 tube – range from RM300-1K/Pair



Rectifier tube - ~rm100-rm200



Driver tube – 6SN7, 1626, pentode, 6SL7, 12AU7… - ~rm100-rm500/pair



Cap: cheap industry cap like WIMA/BC



Socket & connector (RCA + binding post) ~rm 200



Power trans (for power and filament) – rm 200-500



If your budget not too tight I suggest u go for option below:

1) SAC 5K OPT

2) Ampohm pio/ Jensen / mundorf silver oil / AN mylar /pio cu/zn

3) Blackgate for driver/input tube cathode decoupling cap.

4) Power triode /pentode as driver tube. 1626 is a cheap and nice candidate.