If you want to keep all of your gear, then try reducing the signal level between your DAC and preamp by using an autoformer with a fixed attenuation. Technically speaking (and in practice), an autoformer will sound much better than reducing the signal level by means of any type of resistive attenuation. In fact, it may actually improve the sound overall (making it more detailed and dynamic).
Contact Dave Slagle. For $200, you can pick up a pair of AVC (autoformers) and have them wired for any fixed reduction you would like (let's say about -10dB to -15dB might be useful for your case). If you are feeling ambitious, you can get these transformers wound with silver wire at a cost. I believe the transformers are about 1.5" tall, 2.5" wide, and just over an 1" deep. You will need a pair of these to fit. If you're not experienced, have someone who is help you out with this DIY. Ideally, you can get these to fit within your preamp chassis and wire up directly. Otherwise, maybe you can fit them within your DAC's chassis. If not, then this solution probably won't be convenient. Good luck.
http://www.intactaudio.com/atten.html
Contact Dave Slagle. For $200, you can pick up a pair of AVC (autoformers) and have them wired for any fixed reduction you would like (let's say about -10dB to -15dB might be useful for your case). If you are feeling ambitious, you can get these transformers wound with silver wire at a cost. I believe the transformers are about 1.5" tall, 2.5" wide, and just over an 1" deep. You will need a pair of these to fit. If you're not experienced, have someone who is help you out with this DIY. Ideally, you can get these to fit within your preamp chassis and wire up directly. Otherwise, maybe you can fit them within your DAC's chassis. If not, then this solution probably won't be convenient. Good luck.
http://www.intactaudio.com/atten.html