300B amp options

I'm looking to buy a amp that uses the 300B tube. I would prefer too find a kit as I am getting the bug too build my own. But I am open too sugestions as far as amp(s) or an integrated also.

the cheaper ( less expensive ) the better!
Check out the Bottlehead website.
A variation on TWL's suggestion is a 2A3 amp and using Sophia Meshplate 300B tubes with 2.5 V filaments. I have a pair in my Bottlehead parafeed 2A3 amps and they are very nice. That gives you the option to explore 2A3 tubes but does limit you to this specific 300B.

Here are some reasonably priced 300B mono block kits (note that additional shipping is $185US).


These kits can also be ordered in the USA through diycable.com (overseas shipping still applies).

Bottlehead's 300B kits (bottlehead.com) are a bit more money. I own Bottlehead amps myself (Paramour 2A3's along with their Foreplay preamp), but have never heard their 300B models (nor have I listened to the Billies).

My previous amp was a 300B Audion Silver Night (sold along with other gear due to finances) and I am looking forward to owning a nice 300B amp again.

If you are planning on using efficient speakers with an easy load, then you might also look into the Bottlehead 2A3 amps. I am waiting for an iron upgrade to be offered, by Bottlehead, for the Paramours and depending on the price may try this out in the interum. I think that the Paramour 2A3 kits are around $550 now, plus domestic shipping. I am fortunate in that I purchased assembled kits (both the mono blocks and the preamp) on the used market for very little money (just what I needed @ the time) and the young gent that assembled them did a first rate job.

Anyway, the most important thing is to not talk yourself out of a directly heated SET amp (easy enough to do) as the sound from a decent one really has to be heard to be believed.

On a side note you may find the following site interesting in regard to speakers that will mate well with SET amps (both commercial and DIY models in all budget ranges are discussed). There is also a link to a sister site @ the top of the page.


I picked up some inexpensive Japanese Triaxial drivers myself (thrift shop find) that I hope to be using more over the next year (need to build better cabinets) with the 2A3 amps as they are approx. 97 db @ 16 ohms. Even with quality DIY cabinets and cap upgrades they should come in @ well under $200/pr and I have a feeling that they may end up replacing my more expensive speakers (my wife liked the trial run anyway:-).
I'd check out border patrol amps. The finest 300b's I have heard and thats including the pricey Ongaku. They have a massively overbuilt triple choke power supply. If you go the kit route I highly recommend purchasing their power supply. I've read some threads on audio asylum where some DIY's had built this supply so that is a possibility as well.
Both the Bottlehead and Billie are excellent. I have done the Billie. It is an easy kit to build stock. It has loads of modifications that are well documented online. It could probably keep you busy for a year or just leave it stock and it sounds very good. I've heard it pushing about half dozen different speakers and it always does quite well if the speakers are right for it. A nice thing about each of these amps, if you are doing your first DIY, is that there is loads of online info and a forum for each.

You can order the Billie with a power transformer that has a 2.5V filament supply and 320V HT for B+ so you can build a 2A3 or 45 based amp too.

I also suggest the grid choke mod.

I have some info on online electronic resources for tube DIY. Drop me an email if you would like a copy. If you are starting out it might be helpful.

Happy New Year:
I remain,
I would also look at Audio Electronic Supply, a division of Cary Audio. They have a kit for under 1000.00(without tubes), SE1-Signature that can play 300B as well as 2A3 output tubes. I had one in my system for years with no problems at all. I finally upgraded to Cary SET but the SE-1 held it's own against its big brothers. You can go to www.audioelectronicsupply.com for all the information. Good luck, IMO the SET bring you closer to the music and the SE-1 is a great amp to tube roll and experiment.
Get the Billies, with all the goodies. Do the modifications when you are building the kit, and it will save you time later. Be sure to get the TJ Meshplate 300B's. They make these babies sing! Must do modifications include the grid choke mod as mentioned, and also conversion of the SRPP input stage to MU. Cheers!

Great ideas! Thanks for all the help! I will defintiely check out these amps on the net. If I go the kit route I'm sure I'll be back with more questions.
Welborne Labs have some good 300B amp kits, the Laurell MKII's are being closed out at reasonable prices. They also have a new 300B kit that will be available soon based on the Electra Print direct reactace drive design and transformers that looks great and should be very easy to build. I'm sure you will be able to order the amps at many price points depending on the level of the parts quality used. The new amp kit can be found under the newsletter, then you will have to go to the in the pipeline section and scroll down towards the bottom.
I hope this will help you with another option.
Good Luck
Norris Wilson