Recent Posts

21

Crack / Re: replacement transformer installed resistance check problems [resolved]

« Last post by tipatina on Yesterday at 04:05:34 AM »

Hello, Re;above
It worked for a while but the cracking/static noise is back. Id like to pursue sending it for flat rate repair. Im at the end of my abilities and would like to get the kit operational/figure out my mistake(s)
Pleas let me know how to proceed. Thanks

22

Eros Phono / Re: Voltage check assistance

« Last post by phatfish on October 13, 2024, 06:17:49 PM »

Socket C and bottom of C4S

23

Eros Phono / Re: Voltage check assistance

« Last post by phatfish on October 13, 2024, 05:38:14 PM »

Added a couple of build pics to start.  A + B sockets and top of C4S. 

24

Eros Phono / Voltage check assistance

« Last post by phatfish on October 13, 2024, 04:36:24 PM »

Hi there, I could use some assistance as to where to look for issues. 

Checks during the build passed.

Resistance checks pass
All 12 LED lit

IA 217.6 OK
IB 217.2 OK
OA 213.1 HIGH
OB 214.5 HIGH
OC 60.3 LOW
OD 55.97 LOW
OkA 64.1 LOW
OkB 59.7 LOW
OkC .004 LOW
OkD .004 LOW

Many thanks for looking.   

25

Legacy Kit Products / Re: A little help identifying please

« Last post by Doc B. on October 13, 2024, 04:17:50 PM »

Hmm. I'm going to guess that is it a Seduction that was built as a tape head preamp. It looks rather similar to the prototype I built over 20 years ago when I first started to dabble with tape playback electronics. There was a link to an article about the project for many years but it has been lost with time. Perhaps the Wayback might find it.

At any rate, unless you already understand the differences between RIAA and NAB/IEC equalization filters you are not going to find it worth your time to learn enough to modify it for phono use. Better to sell it to someone looking for a tape head preamp and find a Reduction or better yet an Eros, which we currently manufacture.

26

Legacy Kit Products / Re: A little help identifying please

« Last post by Paul Birkeland on October 13, 2024, 03:47:03 PM »

What did the seller say it was?

27

Legacy Kit Products / Re: A little help identifying please

« Last post by thefreight on October 13, 2024, 02:39:09 PM »

Hi all,

I believe I just purchased this exact item….

I was searching for the “PT 1” and came up empty….   I took a chance on it. 

I just came across this forum…. 

I’m obviously pretty nervous after reading the comments….

Not “RIAA anymore” definitely worries me….  I bought it with the intent of using it as a phono pre amp…

Im a newbie with tube pre’s , sorry if my comments/concerns are redundant

28

Eros Phono / Re: Winter is coming!

« Last post by Ivan303 on October 13, 2024, 03:35:14 AM »

Yep, that's what my math says as well. 

For some reason the Cinemag site claims 150 Ohms using the 1:20 taps and 37.5 ohms using the 1:40 tap (my math says 29.3 ohms).  Transformer losses? 

But for sure the Hana 'Blue' sings at 150 ohms (as does a 20 yo Shelter 501 mk II at the same load) and it's enough 'step up' for my current phono preamp.

I added a switch to the front of the 'poor man's Bob's devises' so I could use both. 

Anyone wishing to make their own high quality step up box using Cinemag ore even Octal  plug-in step-up and maybe even the Sowters should check up the offerings at the ebay seller at the above post and link.  $30 for everything you need except the transformers themselves.

29

Eros Phono / Re: Winter is coming!

« Last post by Paul Birkeland on October 12, 2024, 04:56:59 PM »

For a 1:20 step-up, you'll step down the 47K resistors across the RCA jacks by a factor of 400, which is about 120 ohms, plus some copper in there, so the 150 ohm rating seems reasonable.

30

Eros Phono / Re: Winter is coming!

« Last post by Ivan303 on October 12, 2024, 02:00:59 PM »

Currently using a Cinemag 3440A at 1:20 (Cinemag claims 150 Ohms) in a eBay kit box made for Cinemag step ups. Poor man's Bob's devices.

https://www.ebay.com/itm/276408327532?_skw=cinemag&itmmeta=01JA1HB1WREH11J2Q1KBEZY5C0&hash=item405b385d6c:g:essAAOSwyLtmC0Ld&itmprp=enc%3AAQAJAAAA4HoV3kP08IDx%2BKZ9MfhVJKnbqgcd4Emy2uiHVw6zw6jaikNxHcIklr9B2dNQ%2FvvxOxTMVAT52ON23ntSpGh09%2F60R4T%2BCxCv4Cc19PaAfalbRDvJ9CKhGbllAGl1S9WtY%2BA6U59oiT5cmJSJaYkIWyUtbtR2%2Bui2JS1OzYhiFx732GGay1%2BVUvnloPGE49Sc9gBPfNCwO3DNnq3Q9X7vo5AVHKwsXSKno6BoMBmIpRYgcuWouO1RPcAMxnCce4UFbGHVEfFI%2Bs40fOCZNKRGx38cpEer8RLd8ijphAKeY5FP%7Ctkp%3ABk9SR8CerLHQZA

$30 for the box plus the transformers and it sounds great.  And no hummmmm.

Would prefer step ups built into phono stage and maybe the 'better' Cinemag CM-1254.  Looks to be an easy task as the hole size is just right in the Eros 2.

Looks to be an easy, straight forward kit compared to others I've built.  I'm good with populating circuit boards, it's attaching all of those stacked transformers and plastic grommets in small spaces as in the two S.E.X amps that are a pain.