Sounds good. Definitely has the 2203 sound, which is my fav amp for certain styles. How do you think it would go running straight into an interface, DAW and IRs, minus the power amp you are running etc? I have seen some preamps sound okay run that way. I have a JMP 50 replica that I run into a load box and IRs. I kind of prefer to just run a preamp, because I have to really push the JMP and they had a reputation of blowing up when pushed hard, e.g., Angus carries a lorry load of spares on tour and has a repair guy working full time fixing the blown ones. I tend to just use plugin amps instead. They do not quite sound like the amp, but plugins are so easy and do not blow up lol. No kitset 2203 preamp exists as far as i can tell. I have not even found a layout diagram for one. I am not keen to scratch build one -- just changing my amp from shared to split cathode is as technical as I get for now. Surprising there is no kit considering there is probably a lot of players that would want one for running into DAW.
Thanks Aquila! I haven't tried it straight into my interface because of my setup (all preamps go to the power amp in my Marshall 4203 which runs on full volume then into the attenuator). Having it this way I can AB-test all pres which is the best way I think to make my own builds sound the way I like them. If I should run my own built pre straight into DAW, I would probably include a phase inverter tube in the design. Not necessary as an inverter but pushing this gain stage is a part of the full sound. Regarding fear of blowing your JMP 50, have you tried adjusting the bias a little colder? The Marshalls I have (4203 and a 9100 power amp) were biased very cold from the factory, below 50% of max dissipation. It feels like a waste to be afraid of using a good amp like that. 😊
Tjena! Tackar för en bra motivering för det jag har tänkt länga att bygga själv 😃 Jag antar att du bara har trafon för glödspänningen till rören? B+ tar du väl från vanlig nätspänning som du likriktar och fixar en ’centertap’ på?
Hej Bosse! Transformatorn ger all ström som behövs, B+ och 6,3V. Jag har köpt den av ett företag i Litauen, toroid lt, som också lindar efter specifikation, de anpassar transformatorn efter ens behov. Här är en länk till deras sida på Ebay: www.ebay.com/usr/toroid-lt?_trksid=p2047675.m3561.l2559
Iof smidigt att få centertap med från början it från trafon…ch ingen större skillnad prismässigt att ta allt från trafon. Åter igen…ett riktigt coolt bygge!
Thanks Endre! I bought it from this guy www.ebay.com/usr/toroid-lt . He's also made me power transformers for a Vox AC15HW , another for a single ended project and output transformer for that same project. Cheap, custom service and great communication, highly recommended!
@@karlekspsykopat Thanks for the answer. Really consideriing doing the same, but it will be my first "on my own" build. Have built two amps from kits before. Did you just replicate the schematics and sent the signal to an output jack instead of a phase inverter , or did you shape the output signal after the output of the second tube any way?
@@endresletvold5586 I used 2203 schematics mostly from rob robinettes web page and then added a 1M pot before the output jack. It was an easy way to do it and it works.
No. In a 2203 head the presence control is connected from the output transformer to the phase inverter which are parts my preamp doesn't have. I think this feature is more for power amps.
