That came out great. I think he sent me pics of this one. he built the preamp for you as well right?
Oliver Sayes Amplifier Owners Club
- Thread starter StevenZ
- Start date
Speaking of, would love to see an image of your Oliver build slagle former passive pre!
StevenZ
Pending Gold Star Member
Yes, he built the preamp next to it in the photos as well. Unfortunately thinking about selling the amp soon.
Blair builds good gear!
StevenZ
Pending Gold Star Member
It sounds very clean and balanced. He used Heyboer outputs on mine. It’s got a volume control but it’s not exactly an integrated. Needs an external preamplifier to perform best.
StevenZ
Pending Gold Star Member
Very nice! Details please
Thanks guys!
I believe the wood is spalted maple. It's a DHT driving DHT amp that can use either a 10y/26 to drive a 50/300B tube via a switch. Permalloy transformers used for input, interstage coupling, volume (AVC), and output. All the iron was wound by Dave Slagle save for the power transformer which I believe are by Lundahl. Pure silver wire was used for the signal path, AVC, and input transformers. The rest of the wiring is Duelund CAST SN/Cu.
All caps in signal path and power supply are either oil or film. The only electrolytic caps used are for the filament regulators, which I'm guessing are by Rod Coleman. Beefy power supply using 6ax4 dampers and 816 rectifiers. 4&8 ohm speaker taps and 2 headphone outs (high & medium Z).
I believe the wood is spalted maple. It's a DHT driving DHT amp that can use either a 10y/26 to drive a 50/300B tube via a switch. Permalloy transformers used for input, interstage coupling, volume (AVC), and output. All the iron was wound by Dave Slagle save for the power transformer which I believe are by Lundahl. Pure silver wire was used for the signal path, AVC, and input transformers. The rest of the wiring is Duelund CAST SN/Cu.
All caps in signal path and power supply are either oil or film. The only electrolytic caps used are for the filament regulators, which I'm guessing are by Rod Coleman. Beefy power supply using 6ax4 dampers and 816 rectifiers. 4&8 ohm speaker taps and 2 headphone outs (high & medium Z).
Now tbis amp sounds like it would be amazing. Switchable type 50 to 300b. Awesome. Do you know the wpc on the type 50? As I understand type 50 are stunning. I will be interested to hear reports on this amp!
What speakers do you use?
What speakers do you use?
With this setup, the 50 should push just a little over 3W. I hear you can get upwards of 4 but you’d have to run them pretty hard.
Currently using the Omega 3 HO monitors but will prob upgrade when I recoup some funds.
Nice! How do like autoformers vs a traditional resistor pot?
The DHT driving a DHT will typically need some custom iron to get the gain up enough to function properly, or you pay a lot of money for some EML driver tubes. Your typical medium mu DHT will drive a 300B just fine if you have a 1:5 input transformer and a 1:2 interstage transformer, but your sources/preamp need to be happy driving that input transformer.
@Pioneerhip has been experiencing this problem in his 26>46 amplifier. It is not enough to provide adequate voltage gain, you need to be able to drive the following stage.
You can also go to three stages. A couple of small DHTs with a mu of 10 cascaded is plenty to drive a 300B. If you wanted to be really cheeky, you could use a pair of something like the 1H4 to drive a 300B, but have the filament of each 1H4 act as part of the cathode resistor for the 300B to get free DC heating.
Whether someone would like a two stage DHT amp loaded with lots of signal iron, or a two stage DHT amp with EML drivers, or an oddball three stage amp with minimal signal iron is rather hard to predict.
Whether someone would like a two stage DHT amp loaded with lots of signal iron, or a two stage DHT amp with EML drivers, or an oddball three stage amp with minimal signal iron is rather hard to predict.
Similar threads
