Bottlehead Kits > Kaiju Stereo 300B amp

Questions for an upcoming Kaju build

(1/3) > >>

larcenasb:
Hello! Planning my next build, but just have a couple questions:

1) Are there any concerns about using a passive preamp with the Kaiju? I think I remember back in 2010 at a headphone meet, that the AKG K1000 was driven by Paramount monoblocks, which were fronted by a passive preamp….Am I remembering that right? It sounded glorious.

I plan to have this audio chain: DIY point-to-point passive preamp -> Bottlehead Kaiju -> Klipsch Heresy IV

2) Can 6SN7-to-5670 6.3V adapters be used safely in the Kaiju? Such as these:

https://www.ebay.com/itm/193445726979?hash=item2d0a438b03:g:EVkAAOSwiqNbtVLZ&amdata=enc%3AAQAIAAAAwAEoMwKaVxNexYlESXiWEMD9N26YTigyPYHoCo%2BqmiRnu%2F%2FaGgCxJB7KwPZqEB%2Bxwgd8JH14ZYPC7wZnQtkjf1hzemKlj0jfKYOSSruf8PuHy5jN7PaABA7Ym%2F89eB1r0ha6q76nvpAWn14Tvia1hVq2HSqYm2lbyNB1B9Zw3pMqGhtLtwnOuiZxk%2BYobccM3M0A0jzTQi5XaEfCMtP2woUxa3iqTEDYEG5CI2%2BZGJhVQmKBINiysh%2BQx41H2uYx%2BA%3D%3D%7Ctkp%3ABk9SR8r5vPfFYg

Thanks so much for any help, and I’m very excited to build this hopefully in the near future. Cheers!

Paul Birkeland:
The question of using a passive preamp depends on the sources you're using (in particular the output impedance of each source), the impedance of the passive control, and the lengths of your cables (the capacitance per foot is important).  You can analyze all of these datapoints together and make some decisions based on the data, but keep in mind that once you want to add a new source, you need to go back and reanalyze that again. 

I do not see any issues with using those adapters.  The 6SN7 will have lower gain, but beyond that there shouldn't be any issues.

larcenasb:
Thanks so much, Paul. Had no idea a passive preamp is a little finicky… Could you please point me in the right direction to get more info on how calculate this and how to understand the numbers/data? Thanks and have a great weekend! :)

Paul Joppa:
The reduced gain with a 6SN7 is a potential problem.

Stock Kaiju needs 1.56 volts RMS to drive it to full power; with a 6SN7 it will need 2.70 volts.

The original standard for CD players is 2.00 volts, which is not enough for the 6SN7. Phono preamps are often lower in output voltage, and phones, iPads, etc can be even lower. Check the specs on your source devices!

Of course, you might never need full power with sufficiently sensitive speakers  like the Heresy.

larcenasb:
Hi PJ! Thanks for making sure, just in case, that I’m informed about the drop in power. I appreciate it!

My room is 12’x15’ w/ 8’ ceilings. And my sources will be:

- VPI Cliffwood w/ Nagaoka MP-150 -> Pro-Ject Tube Box S2
- PS5 -> TV -> Schiit Bifrost 1

Navigation

[0] Message Index

[#] Next page