i just rented a yorkville xs 400 bass soild state head with preamp tubes. this was my first soild state amp with the tubes and a really loved how it gave a warm sound to my tone. since then i have decided that i would need an amp that has preamp tubes in it, but i have been unable to find a sutible one so far. i have found some bass pedals that do have preamp tubes in them and r unsure about how well they replicate the actual tube sound. please give suggestions on amps or pedals. i have a limited budget.