Recent Posts

1

Eros Phono / Re: Input impedance (resistor value changes)

« Last post by Ivan303 on Today at 05:33:30 AM »

Thanks Paul,

What I suspected and likely I'll just stay with the 1:20 step-up.

2

Stereomour / Re: Tube biasing for the older Stereomour

« Last post by Paul Birkeland on Today at 05:31:31 AM »

https://www.aliexpress.us/item/3256808416810940.html?spm=a2g0o.productlist.main.13.33587afdZEBydd&algo_pvid=467b3318-7a09-44ec-824a-55396c8a316b&algo_exp_id=467b3318-7a09-44ec-824a-55396c8a316b-6&pdp_ext_f=%7B%22order%22%3A%22-1%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21USD%2195.98%2171.98%21%21%21692.00%21519.00%21%402101ef5e17427438541158525ec6b4%2112000045912706774%21sea%21US%211982106386%21X&curPageLogUid=T7LOj3d4BRJQ&utparam-url=scene%3Asearch%7Cquery_from%3A

The 300B version of that tube performed really well in a shootout I had a few years ago. 

3

Eros Phono / Re: Input impedance (resistor value changes)

« Last post by Paul Joppa on Today at 04:49:17 AM »

Here is a really good reference on step-ups:

http://www.rothwellaudioproducts.co.uk/html/mc_step-up_transformers_explai.html

From  the viewpoint of the preamp itself, there is no reason not to change the input load resistor from the 47K stock value , as long as it's less than 1 Megohm. 

4

Eros Phono / Input impedance (resistor value changes)

« Last post by Ivan303 on Today at 04:07:37 AM »

Planning on installing built-in step-ups from Cinemag.  Currently having very good luck with the step-up box built using  a pair of 3440AH with a toggle for 150 Ohm/37.5 Ohm even though the cartridge I'm currently using seems to prefer (if the reviewers are correct) to see about 100 Ohms.

Cinemag will do costume winds and those are likely done by David Geren himself?  Also a few more $$$.

And they answer questions via email!

So the question would be, dare I lower the input impedance of the Eros 2 to about 33K as opposed to the 47k as currently built to get to about 100 Ohms  using the 1:20 winding?  Would not worry much about going higher but....

With all of the gain available in the Eros 2, gain is not a problem and the 1:20.

Maybe just go with the 1:20 winding and be happy?

5

Stereomour / Re: Tube biasing for the older Stereomour

« Last post by Pkay on Yesterday at 09:48:53 PM »

Any suggestions for tubes would also be appreciated.

6

Stereomour II / Re: Right Channel Hum

« Last post by Paul Birkeland on Yesterday at 02:48:43 PM »

Can you post some photos of what you're seeing?

7

Stereomour II / Re: Right Channel Hum

« Last post by thoven0215 on Yesterday at 01:35:10 PM »

Apologies for the 3 year response time. I was finishing up school. After re-reading the thread and re-checking the voltages, IB and OB are at around 0.9 volts. KReg on the B side is about 0.9 volts. 34U is also at 0.9 volts. I may have not checked the lower voltage settings on my multimeter at the previous time. You said that

IB is fed from a high voltage node in the power supply.  If that node is pulled to 0V, you will burn up resistors pretty much immediately and you'll know there's a problem.  Since you haven't reported that this happened, you either do not have IB connected to the correct spot, or that wire is broken.

and on reply 12 I stated that the resistor next to the capacitor on the B side started to smoke as I checked the voltages. Could this be what you are talking about? I also used my continuity checker on my multimeter and it says that 34U and IB are connected. Thanks for your help as always.

8

Crack / Re: Speedball 1.1 PDF

« Last post by Paul Birkeland on March 21, 2025, 03:20:26 PM »

You'd want to e-mail replacementparts(at)bottlehead(dot)com to request another download link.  Be sure to provide your name and order number with your e-mail. 

-PB

9

Crack / Speedball 1.1 PDF

« Last post by bingobango on March 21, 2025, 09:46:35 AM »

I've placed an order on March 11th, and in anticipation of the Crack and Speedball arriving I've wanted to download and review the manuals. I was able to download the Crack 1.1 Manual PDF, however the Speedball 1.1 Manual PDF says I've reached my download limit. The issue is that I wasn't able to download or even access the PDF. I have clicked the link in my email which may have expired my token, but I'm still needing the PDF.

Any assistance would be appreciated!

10

Moreplay / Re: Schiit Gjallarhorn

« Last post by Dhouse7516 on March 21, 2025, 07:06:15 AM »

Thanks, Paul.