Just completed the Tu-8550 pre-amp with 4X Mundorf supremes. It’s a great companion to the tu-8900 . It neither enhances nor detracts from the tu-8900 sound. This is the best sounding Elekit combo I've heard thus far. Amazing sound!
I built this the first week on an extended time away from home without brining any audio equipment, only half of my soldering tools. Built stock, but intend to upgrade to CuTF caps in a few days. Original caps were installed high enough to allow easy cutting of leads.
Victor's service is worth more than trying to save a few dollars without premium output transformers.
I had a question on a Saturday night at 18:00 and he got back above and beyond expectations. I don't expect other businesses to have weekend staff. Saturday night question, Monday noon reply would be the best that should be expected.
Speakers are cheap stuff I was able to find in Bellingham capable of 94 dB w/m . I'm not used to them, the new listening space.
Sound is dependent on source. Some I don't expect to sound good is magic. Some is "can't wait to hear this" to "meh".
I've only used the pair of Amperex Holland 1970's build so far, but look forward to trying to the Sylvania and French tubes obtained from Victor.
I inherited about 1,000 tubes in 2020. The RCA pair of 2A3's are what caught my eye. I paid to have them tested and they tested as "new" (see last photo and question, one of hundreds of my uncle's projects - same pair?... will never know other than the had more than one of those chassis in his crawl space)
If anyone can interpret the code of this base for date I would appreciate it. I've found that is was 1943 production by some being sold but research is inconclusive. I always thought they were grey plate, but seller with same code had black plate listed. In the right light I would call them black, but doubt it.
Really enjoying the sound. Way more volume than I can get away with living in a condo... maybe not right now, it's happy hour and have it at 2:30.
Using without NFB.
The silver solder Victor sells is more difficult to use than silver lead combo's, easier would be without silver. I retouched every joint and marked each to be sure I didn't miss any.
Read the instructions from front to back. Glancing over it you might miss something that would have saved some time.
Victor's service is worth more than trying to save a few dollars without premium output transformers.
I had a question on a Saturday night at 18:00 and he got back above and beyond expectations. I don't expect other businesses to have weekend staff. Saturday night question, Monday noon reply would be the best that should be expected.
Speakers are cheap stuff I was able to find in Bellingham capable of 94 dB w/m . I'm not used to them, the new listening space.
Sound is dependent on source. Some I don't expect to sound good is magic. Some is "can't wait to hear this" to "meh".
I've only used the pair of Amperex Holland 1970's build so far, but look forward to trying to the Sylvania and French tubes obtained from Victor.
I inherited about 1,000 tubes in 2020. The RCA pair of 2A3's are what caught my eye. I paid to have them tested and they tested as "new" (see last photo and question, one of hundreds of my uncle's projects - same pair?... will never know other than the had more than one of those chassis in his crawl space)
If anyone can interpret the code of this base for date I would appreciate it. I've found that is was 1943 production by some being sold but research is inconclusive. I always thought they were grey plate, but seller with same code had black plate listed. In the right light I would call them black, but doubt it.
Really enjoying the sound. Way more volume than I can get away with living in a condo... maybe not right now, it's happy hour and have it at 2:30.
Using without NFB.
The silver solder Victor sells is more difficult to use than silver lead combo's, easier would be without silver. I retouched every joint and marked each to be sure I didn't miss any.
Read the instructions from front to back. Glancing over it you might miss something that would have saved some time.
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Yep ! I initially had mine backwards too because I followed others pics on here .
Victor advised that the vcaps install backwards from most of the other brands. Green wire should be pointed towards the front of the stereo unit !
Victor advised that the vcaps install backwards from most of the other brands. Green wire should be pointed towards the front of the stereo unit !
- VCAP CuTF installation note:
- The green lead indicates the outermost foil, and should be connected to the lowest impedance path to ground. Another way to identify outer foil is the writing on the label flows towards the outer foil. Please not not mix up with the Audio Note Silver Cap..
Hi There!
I bought the TU8900 and want to put OPT Hashimoto HC203U on them, 3.5K is this possible?
Thanks for the answer allready.
Mojo Teake
I bought the TU8900 and want to put OPT Hashimoto HC203U on them, 3.5K is this possible?
Thanks for the answer allready.
Mojo Teake
I am curious why you would want to use Hashimoto instead of Victor's excellent Lundahl transformer upgrade?
Hashimoto makes fine transformers no doubt (my Sunvalley SV-S1645D uses Hashimoto) but I find the Lundahls in the TU-8900 are an extremely fine sounding and proven option.
Steve Z
Hashimoto makes fine transformers no doubt (my Sunvalley SV-S1645D uses Hashimoto) but I find the Lundahls in the TU-8900 are an extremely fine sounding and proven option.
Steve Z
Here is a link to the LL2785C datasheet at the Lundahl website. If you have a data sheet or measurements for your Hashimoto transformer, you could compare and decide from that whether the Hashimoto is suitable: https://www.lundahltransformers.com/wp-content/uploads/datasheets/2785C.pdf
Here is the link to the Hashimoto catalog if you don't have a datasheet for your transformer.
http://hashimoto-trans.co.jp/frame/tubecateng22.pdf
Looking at the listing for the Hashimoto HC203U it is shown as 2.5K ohms not 3.5K. It is shown as compatible with the following output tubes:
300B, EL-34, 2A3, 6B4G, 6L6GC, 6A3
http://hashimoto-trans.co.jp/frame/tubecateng22.pdf
Looking at the listing for the Hashimoto HC203U it is shown as 2.5K ohms not 3.5K. It is shown as compatible with the following output tubes:
300B, EL-34, 2A3, 6B4G, 6L6GC, 6A3
I don't know whether this is the right plot to look at, but assuming it is, the power output would go down a little bit for the same grid modulation.
Datasheet for 6l6GC at https://frank.pocnet.net/sheets/127/6/6L6GC.pdf .
I just noticed the Hashimoto table shows two primary impedance options (taps/windings, I assume) for this transformer, one with 2.5kOhm and the other with 3.5kOhm. So, just pick the 3.5kOhm one.
Edit: Oops, just realizing I confused the 8900 and the 8200. The plot above is for 6L6GC tubes, as in the 8200.
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I think you answered your own question with the graph you posted. You could get more power safely through a transformer with lower load resistance and higher current capability, but power out is also dependent on your output tube plate characteristics and its safe power dissipation rating.
It's too late to edit my 6L6GC post above, but here is the datasheet link for the 300B from the Western Electric website: https://static1.squarespace.com/sta...45504889f6da688b7c8ecd/1598378059729/300B.pdf
From the last page it looks like as you vary the load from 2.5kOhm to 3.5kOhm you reduce power and distortions, but there doesn't seem to be anything drastic happening. There is no distortion minimum, like for the 6L6GC near 3.6kOhm.
From the last page it looks like as you vary the load from 2.5kOhm to 3.5kOhm you reduce power and distortions, but there doesn't seem to be anything drastic happening. There is no distortion minimum, like for the 6L6GC near 3.6kOhm.
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